Physics p2 Essay

Physics 4321 [Paper 2 Section B]

http://www.ssijbfizikspm.blogspot.com Prepared by: En Adnan Shamsudin

PAPER 2 SECTION B & C

CHAPTER 2

1. Diagram 9.1 shows the effect of a man falls from a

high position to the ground without opening the

parachute. Diagram 9.2 shows a man with the same

mass falls from the same height when the

parachute is open.

Diagram 9.1 Diagram 9.1

(a) (i) What is the meaning of free fall?

[ 1 mark]

(ii) Based on diagram 9.1 and Diagram

9.2, compare the acceleration, the rate

of change of momentum and the time

of impact.

Relate the rate of change of momentum

with the time of impact to make

deduction on the relationship

between the acceleration and the rate

of change of momentum.

[ 5 marks]

(b) A hovercraft moves on a cushion of air

which is trapped underneath it, as shown

in Diagram 9.3. The trapped air reduces

the friction. The hovercraft starts from

rest and as it starts, the propeller

produces a forward force until it reaches

a constant velocity .

Diagram 9.3

(i) Sketch a velocity-time graph to

show the motion of hovercraft.

(ii) Explain why the hovercraft

moves with constant velocity in

terms of the force acting on it

[4 marks]

(c) Diagram 9.4 shows a canoe

Diagram 9.4

You are required to give some suggestions to

design a canoe which can travel faster and

safer . Using the knowledge on motion,

forces and the properties of materials, explain

the suggestions based on the following

aspects:

(i) the surface of the canoe

(ii) the shape of the canoe

(iii) the material of the canoe

(iv) the material of the canoe

(v) the material of the canoe

[ 10 marks ]

2. Diagram 9.1 shows a car and a lorry stopping at a

red traffic light. When the traffic light turns green

as in diagram 9.2, the car is found to move ahead

of the lorry.


(a) What is meant by mass?

[ 1 mark ]

(b) Based on diagram 9.1 and 9.2, compare the

masses of the vehicles and their ability to

speed ahead. Relate the mass of the vehicle

and the way it can start moving from rest to

deduce a concept in physics with regard to the

motion of objects.

State the physics concept.

[ 5 marks ]



(c) Based on the physics concept stated in (b), (i)

explain why a driver lurch forwards when a

car he is driving comes to a sudden stop, (ii)

describe and explain a method which can

overcome the situation in (c)(i).

[ 4 marks ]

(d) Diagram 9.3 shows a water rocket made from

an empty 1.5 litre plastic soft drink bottle by

adding water and pressurizing it with air for

launching.

Diagram 9.3

The objective is to keep the rocket in the air as

long as possible. Using the appropriate

physics concepts, suggest and explain suitable

designs based on the characteristics of

(i) the acceleration,

(ii) the shape

(iii) the structure

(iv) the buoyant force (upthrust),

(v) the stability of the motion, to improve

the water rocket.

[ 10 marks ]

3. Diagram 11.1 shows ‘Newton’s cradle’ which

consists of five identical balls suspended in a row

from a wooden frame by wires.

Diagram 11.1

When the ball on left end is pulled aside (Diagram

11.2) and allowed to fall, the ball on the far end is

knocked away from the others with the same speed

as the first ball (Diagram 11.3).


(a) Name the physics principle involved which

makes the ball on the other far end is knocked

away from the others.

[1 mark]

(b) Explain, in term of momentum and energy transfer,

why the ball on the opposite end is knocked away

from the others.

[4 marks]

(c) Diagram 11.4 shows five designs of ‘Newton’s

Cradle’, P, Q, R, S and T, with different

specifications. You are required to determine the

most suitable design to make the ball at the end

swings up to higher level and at bigger speed. Study

all the five designs from the following aspects:

(i) The arrangement of the balls

(ii) The type of material used to make the balls

(iiii) The number of string used to hang the balls

(iv) The position of the ball to start the

oscillation



Diagram 11.4

Explain the suitability of the aspects. Justify your

choice..

[ 10 marks]

(d) In a game, a 50 g white ball of speed 0.8 m s-

1 hits a 30 g red ball at rest . If the white ball

stops after the collision, calculate;

(i) the velocity of the red ball after the

elastic collision.

(ii) the change of the momentum of the

white ball.

(iii) the impulsive force acting on the

white ball during the collision if it is

stopped in 0.05 seconds.

[5 marks]

4. Diagram 9.1 shows the initial and final position of

a student sliding down a slide. Diagram 9.2 shows

the initial and final position of the same student

sliding down the slide from a different initial

position.

(a) (i) What is the meaning of gravitational

potential energy of the student?

[1 mark]

(ii) Observe Diagram 9.1 and Diagram 9.2.

Compare the initial position of the

student and the speed of the student on

reaching the final position.

Relate the speed of the student on

reaching the final position with the

energy gained by the student to make a

deduction on the relationship between

the initial position and the energy

gained.

[4 marks]

(iii) Name the physics principle that explains

the situation in (a)(ii).

[1 mark]



(b) Diagram 9.3 shows a baby sleeping in a

cradle. The cradle is made to oscillate

between position P and Q through the

equilibrium position O.

Diagram 9.3

(i) State the changes in energy that occur when

the cradle swings from P to O, and then

from O to Q.

(ii) After some time, the cradle stops oscillating.

Explain why.

[4 marks]

(c) Diagram 9.4 shows an archer getting ready to

shoot an arrow towards a target board from a

far distance. When he releases the arrow, he

observes that the arrow falls short of the

target.

Diagram 9.4

Suggest and explain how he would be able to shoot

the arrow to hit the centre of the target board,

based on the following aspects:

(i) The strength of the cord

(ii) The force constant of the bow

(iii) The material used for the bow

(iv) The design of the arrow

(iv) The way the arrow is aimed at the target

[10 marks]

5. Diagram 11.1 shows a balloon taped to straw.

Diagram 11.1

(a) When the paper clip is removed, the balloon

propels forward.

(i) Name the principle used in the

propulsion of the balloon.

[ 1 mark ]

(ii) Explain what makes the balloon

propel forward.

[ 4 marks ]

(b) The balloon moves with an initial velocity of

4 ms-1

. Then it decelerates for 2 seconds and

finally stops.

(i) Sketch a velocity-time graph for the

motion of the balloon.

(ii) Calculate the deceleration of the

balloon.

(iii) Calculate the distance travelled.

[ 5 marks ]

Diagram 11.2 shows four racing cars , P , Q ,

R and S, with different specifications. You are

required to determine the most suitable car to

complete in the Formula 1 Summer Race.

Diagram 11.2

Study the specifications of all racing cars from

the following aspects:

(i) The shape of the car

(ii) The ridges on the tyres

(iii) The engine power

(iv) The material for the body of the car.

(v) Explain the suitability of aspects. Justify

your choices.

[ 10 marks ]



6. (a) Diagram 9.1 shows two identical feeding

bottles floating in liquid P and liquid Q

respectively. The feeding bottle floats

because the net force acting on the bottle

is zero.

Diagram 9.1

(i) What is the meaning of net force?

[ 1 mark]

(ii) Using Diagram 9.1 compare the position of

the bottles in liquid P and liquid Q. Compare

also the weights and the buoyant forces that

are acting on the bottles in liquid P and

liquid Q. Compare the density of liquid P

and liquid Q.

Relate the position of the bottle and the

density of liquid to deduce a relevant

physics concept.

[5 marks]

(b) Diagram 9.2 shows a simple hydraulic

jack.

Diagram 9.2

Explain how load M can be lifted and

give a reason why the cross sectional area

of piston A is smaller than the cross

sectional area of piston B.

[4 marks]

(c) The simple hydraulic jack in Diagram 9.2

is not suitable to use to lift a car in a

workshop.

Using suitable physics concepts, explain

the required modification that need to be

done to enable the machine to lift a car

easily in a workshop.

You can emphasise on the following

aspects in your modification;

(i) method so that only small force

is applied at piston A

(ii) component to control flow of

liquid in the hydraulic jack

(iii) component in the hydraulic jack

to lowered the car

(iv) size of pistons

(v) type of liquid used

[ 10 marks ]

7. Diagram 9.1 shows a hydraulic lift used to raise

loads Q and R.

(a) (i) What is meant by pressure?

[1 mark]

(ii) A force of 100 N is used to push

down piston P and able to raise

piston Q and piston R. With

reference to Diagram 9.1

compare the pressure acted on piston

Q and R, the cross sectional area and

the force produced at the piston Q and

piston R.

Relate the cross sectional area of the

pistons with the force produced on the

pistons.

Name a physics principle relating the

cross sectional area and the force

exerted on pistons Q and R.

[5 marks]

(b) Diagram 9.2 shows a cross section of an

aeroplane wing. The wing help the aeroplane

to be lift up when the plane speeding along

the runaway.



Name the shape in Diagram 9.2 and explain

how the aeroplane can be lifted up to the air.

[4 marks]

(c) Submarine is used to move underwater.

Using suitable physics concepts, explain

how you can design a basic structure of a

small submarine so that it can be used for

an underwater exploration.

The design should include the following

aspects:

(i) the material and thickness of the wall,

(ii) shape of the submarine,

(iii) able to submerge,

(iv) the equipments to detect underwater

obstacles and depth

[10 marks]

8. Diagram 11.1 shows a submarine floating in sea

water due to the effect of buoyant force.

Diagram 11.1

(a) What is the meaning of buoyant force?

[ 1 mark ]

(b) Explain how a submarine is able to

submerge into deep sea water.

[ 4 marks]

(c) You are asked to investigate the

characteristics of four submarines shown in

Table 11.1.

Explain the suitability of each characteristic

of the submarines and determine the

submarine which can travel faster, stay l

onger in deeper sea water and able to carry

more crew.

Give reasons for your choice.

[ 10 marks ]

(d) Diagram 11.2 shows oil drum floats

stationary in water. The density of water is

1000 kg m-3

.

Diagram 11.2

Calculate

(i) The volume of the oil drum immersed in

water.

[ 2 marks ]

(ii) The buoyant force acting on the oil drum.

[ 2 marks ]

(iii) The mass of the oil drum.

[ 1 mark ]



9. Diagram 11.1 shows an aeroplane. Diagram 11.2

shows a cross section of the aeroplane’s wing.


(a) Name the shape of the cross sectional of the

aeroplane wing.

[1 mark]

(b) The aeroplane can be lifted up when flying

due to a difference in pressure of the air

between the upper and bottom sides of the

wings.

(i) Explain how this difference in

pressure is produced.

[ 3 marks]

(ii) Name the principle involved in your

answer in (b)(i).

[ 1 mark ]

(c) Table 11 shows characteristic of four designs

of the aeroplane wings.

Table 11

You are requested to choose the most suitable

wing to be installed to the body of an

aeroplane.

By referring to the information given in Table

11, explain the suitability of each

characteristic and suggest the most suitable

wing to be installed with the body of the

aeroplane.

[ 10 marks ]

10. Diagram 11.1 shows the air balloon which is used

as a weather balloon to carry a radiosonde

instrument for collecting data about the

atmosphere. The weather balloon rises up in the air

due to Archimedes’ principle

(a) (i) State Archimedes’ principle.

. [1 mark]

(ii) Explain why a weather balloon that is

rising up in the air will stop at certain

altitude.

. [4 marks]

(b) Diagram 11.2 shows four hot air balloons

P,Q,R and S with different features. You

are required to determine the most

suitable the most hot air balloon which is

able to carry three or four people to a

higher altitude in a shorter time.



Study the characteristics of all the four hot air

balloons from the following aspects:

- The size of the balloon

- The number of burners

- The type of the fabric of the balloon

- The temperature of the air in the balloon

Explain the suitability of the aspects. Justify your

choice.

[10 marks]

(c) Diagram 11.3 shows a balloon which

contains helium. The volume of the balloon

is 1.2 m3. Density of helium gas is

0.18 kgm-3

.

Diagram 11.3

(i) By neglecting the mass of the balloon,

calculate the mass of helium gas in

the balloon.

[2 marks]

(ii) Calculate the buoyant force which

acts on the balloon.

(Density of air is 1.3 kg m-3

)

[3 marks]

11. Diagram 9.1 and Diagram 9.2 show the heating

curves obtained when 50 g and 80 g of the solid

substance are heated respectively. The melting

point of the substance is 78o

C.

Diagram 9.1

Diagram 9.2

(a) (i) What is the meaning of melting point?

[1 mark]

(ii) Based on the information and the observation

on Diagram 9.1 and Diagram 9.2, compare the

mass, the time taken to reach the melting

point and the time taken by the substance to

change into liquid completely.



Relate the mass and the time taken by the

substance to change into liquid completely to make

a deduction on the relationship between the mass

and the latent heat of fusion absorbed by the

substance.

[5 marks]

(b) Diagram 9.3 shows the phenomenon of sea

breeze.

Diagram 9.3

Using the concept of specific heat capacity,

explain how the phenomenon of sea breeze

occurs.

[4 marks]

(c) Diagram 9.4 shows a design of central heating

system used in cold country to heat and keep

houses warm.

Diagram 9.4

Suggest and explain how to build a house

central heating system which can function

effectively based on the following aspects:

(i) The specific heat capacity of the

liquid

(ii) The boiling point of the liquid

(iii) The properties of material used for

transmission pipe

(iv) The size of the fan used to blow

the heat from radiator

12. Diagram 9.1 shows a boy pouring hot coffee into a

cup. The hand of the boy is not scalded by the

coffee droplets that are spattered from the kettle.

Diagram 9.2 shows hot coffee spilling over and

getting onto his hand and his hand gets scalded

because of the higher heat capacity in it.


(a) What is meant by heat capacity?

[ 1 mark ]

(b) (i) Observe Diagrams 9.1 and 9.2.

Compare the temperature of the

coffee, the mass of

the coffee droplets spatters on his

hand and the coffee from the kettle

spills on it, and the injury to the

hands.

State the relationship between the

mass of the coffee and the injury that

occurs.

[ 4 marks ]

(ii) State the relationship between the heat

capacity and the mass.

[ 1 marks ]

(c) Diagram 9.3 shows a radiator of a car

Diagram 9.3

Water is used as a cooling agent in a radiator.

Explain how water is used

[ 4 marks ]



(d) You are required to give some suggestions to

design an efficient thermometer to be used in

physics laboratory.

Using your knowledge about heat and

properties of materials, explain how to built a

thermometer which can function effectively

based on the following aspects,

(i) Strength of the thermometer

(ii) Choice of the thermometric liquid

(iii) Sensitivity of the thermometer

(iv) Design of the thermometer so that the

scale can easily be read.

(v) Melting point and freezing point of

the liquid

[ 10 marks ]

CHAPTER 5

13. Diagram 11.1 shows Ali standing at the side of a

pond. Ali can see the image of the fish and the

image of the dragon-fly in the water as shown by

the ray diagram.

Diagram 11.1

(a) (i) What is the meaning of virtual image?

[1 mark]

(ii) Explain how Ali can see the image of

the fish and the image of the dragon-

fly. State the phenomenon of light that

is involved in each case.

[4 marks]

(b) (i) Calculate the angle and . θ α

[ Refractive index of water is 1.33 ]

[4 marks]

(ii) State one characteristic of the image of

the dragon-fly.

[1 mark]

(c) Table 11 shows the design of five torchlights

P, Q, R, S and T.

Table 11

You are asked to investigate the characteristics of

the five torchlights shown in Table 11. Explain the

suitability of each characteristics of the torchlight

and determine the torchlight which can produce a

strong parallel beam of light.


[10 marks]

14. Diagram 11.1 shows two convex lenses, P and Q,

used in an astronomical telescope. The focal length

of P is 40 cm and for Q is 10 cm

Diagram 11.1



(a) What is the meaning of focal length of lens ?

[ 1mark ]

(b) By using suitable apparatus, explain how the

focal length of both lenses can be estimated.

[ 4 marks ]

(c) Diagram 11.2 shows an arrangement of lenses

to construct a simple astronomical telescope

using lens P and lens Q.

Diagram 11.2

You are asked to investigate the arrangement

and characteristics of the lenses used to

construct the simple astronomical telescope as

shown in Diagram 11.3.

Diagram 11.3

Explain the suitability of the arrangement and

each characteristics of the lenses and

determine the arrangement which can produce

the brightest and sharp image at normal

adjustment.

(d) A camera has a convex lens of focal length 5

cm is used to capture an object of 1 m in

height and 4 m from the camera.

(i) determine the image distance from the

camera

[2 marks]

(ii) Calculate the height of image

produced in the camera

[2 marks]

(iii) State the characteristics of image formed

in the camera

[1 marks]

15. Diagram 11.1 and 11.2 show two photographs

captured using two lenses with different focal

length.


(a) (i) What is meant by focal length?

[ 1 mark ]

(ii) Using Diagram 11.1 and Diagram

11.2, compare the thickness and the

focal length of the lenses. Explain the

relationships between the thickness

and the power of the lens.

[4 marks]

(b) An object is placed 30 cm in front of a lens

with a power of + 5 D.

(i) An object is placed 30 cm in front of a

lens with a power of + 5 D.

[ 2 marks ]

(ii) Calculate the distance of the image.

[ 2 marks ]

(iii) Calculate the magnification of the

image

[ 1 mark ]

(c) Diagram 11.3 shows an astronomical

telescope. An astronomical telescope is used

to view very large objects like moon.

Table 11.1 shows the characteristics of four

different simple astronomical telescopes.



Explain the suitability of each characteristic of

the telescope and determine the most suitable

telescope to be used to observe very far object.

Give reason for your choice.

[ 10 marks ]

16. Total internal reflection occurs when light travels

from a denser

medium to less dense medium and the angle of

incidence is greater

than the critical angle.

(a) What is the meaning of critical angle?

[1 mark]

(b) (i) Write an equation to show the

relationship between the critical

angle, c, and the refractive index, n, of

a medium.

(ii) Use the equation in (b)(i) to explain

why total internal reflection is easier

to occur in diamond than in glass.

[ Refractive index of glass = 1.5,

refractive index of diamond = 2.4 ]

[4 marks]

(c) Diagram 11.1 shows a ray of light from an

object at point P at the bottom of a swimming

pool travelling from water into the air.

Diagram 11.1

Calculate,

(i) the refractive index of the water in the

pool.

(ii) the apparent depth of the image.

[5 marks]

(d) Diagram 11.2 shows a glass window which

opens outwards at an angle θ.


Diagram 11.3 shows the side view of the

window. If rays of sunlight incident on the

window undergo total internal reflection at

points like X, direct sunlight would not be

able to enter the room and it would be cooler.

Four designs P, Q, R and S of the window are

available and are designed such that it can be

opened at a maximum angle of θ.

Table 11 shows the characteristics of the glass

used and the angle θ of each design.

Table 11


the glass and the size of the angle θ and

determine the most suitable design to be used so

that the room would be kept cool during the day.


[10 marks]



17. Diagram 11.1 shows a stamp collector examines a

stamp using a magnifying glass.

Diagram11.1

Table 11 shows characteristics of four types of

magnifying glass

Table 11

(a) What is meant by the focal length?

[1 mark]

(b) You are requested to choose the magnifying

glass to be used by a stamp collector to

examines the stamps.

By referring to the characteristics given in

Table 11, explain the suitability of each

characteristic and suggest the most suitable

magnifying glass to be used by a stamp

collector.

[10 marks]

(c) A student is using a magnifying glass M to

observe a small ant at a distance of 2 cm.

(i) Calculate the image distance.

[2 marks]

(ii) Determine the linear magnification of

the image of the ant.

[2 marks]

(d) You are given a convex lens. Describe how

the power of the lens can be determined.

State the relationship between power and

focal length of a lens.

[5 marks]

18. Diagram 9.1 and Diagram 9.2 show the identical

objects located at different positions in front of

identical concave mirror. Real images with

different sizes are produced.


(a) (i) What is the meaning of real image?

(ii) Using Diagram 9.1 and Diagram 9.2,

compare the object distance, the size of

image formed and the image distance.

Relate the position of the object distance

and the size of the image formed to make

a deduction on the relationship between

the object distance and the magnification

scale.

[ 5 marks ]

(b) Diagram 9.3 shows a photograph of a concave

mirror producing upright and magnified

image.

Diagram 9.3

Draw a ray diagram to show the formation of

the image formed as shown in Diagram 9.3.

(c) Diagram 9.4 shows a ray diagram of a

slide projector.



Diagram 9.4

The slide projector is needed in your school

hall. You are required to modify the slide

projector so that it can produce clearer

image and can be seen by 800 students.

Suggest and explain based on the following

aspect:

(i) The power of the bulb used.

(ii) The position of the bulb from the

concave mirror.

(iii) The curvature of the concave mirror.

(iv) The position of the slide from the

projector lens.

(v) Position of the screen from the

projector.

[ 10 marks ]

19. Diagram 9.1 and Diagram 9.2 show light rays from

two identical objects passing through two identical

convex lens. Both lenses produce real images. F is

the focal point for the lens.

(a) (i) Name the phenomenon involved.

[ 1 mark ]

(ii) Observe Diagram 9.1 and Diagram 9.2.

Compare the object distance, the size of

the image and the power of the lens.

Relate the size of the image with the

object distance.

[ 1 mark ]

(b) Diagram 9.3 shows the structure of a simple

camera.

(i) Explain how the camera is able to capture

the image of a distant object.

[ 3 marks ]

(ii) State the range of the object distance

where the image formed is sharp.

[ 1 mark ]

(c) A student is given two convex lenses , R and

S. The focal length of R and S are 20 cm and

5 cm respectively. Suggest and explain how to

build a microscope which produces a sharp

image and magnified image based on the

following aspects:

(i) Arrangement of lenses

(ii) Position of object

(iii) Position of the first image

(iv) Distance between two lenses.

[ 8 marks ]

(d) Suggest two modifications that need to be

done to the microscope to produce a bigger

final image.

[ 2 marks ]



20. Diagram 9.1 and Diagram 9.2 show the parallel

rays of light directed towards the convex lenses J

and K. Both the lenses produce real images. F is

the focal point for each lens.

(a) (i) What is meant by focal length?

[1 mark]

(ii) With reference to Diagram 9.1 and

Diagram 9.2, compare the thickness

of the lenses and the effects it has

on the refracted rays to make a

deduction regarding the relationship

between the thickness of the lenses

and their focal length.

[5 marks]

(b) Diagram 9.3 shows the ray diagram of a

simple microscope.

Diagram 9.3

(i) State the function of the eyepiece.

[1 mark]

(ii) State the characteristics of the image

formed by a microscope.

[3 marks]

(c) You are given two convex lenses S and Q of

different focal length. Lens S has a longer

focal length than lens Q.

(i) Using the two lenses above explain

how are you would make a simple

astronomical telescope.

[4 marks]

(ii) Suggest modification that need to be

done on the telescope to produce

clearer and bigger images.

[6 marks]

21. Diagram 9.1 shows a light ray passing through

from air into water. Diagram 9.2 shows a light ray

passing through from air into glass.

[Refractive index: Glass= 1.50 , Water=1.33]


(a) (i) Name the phenomenon of light as

shown in Diagram 9.1 and Diagram 9.2.

[ 1 mark ]

(ii) What is the meaning of refractive

index?

[ 1 mark ]

(b) Observe Diagram 9.1 and Diagram 9.2.

Compare the refractive index, the density and

the angle of refraction of light ray. Relate the

density of medium with the angle of refraction

to make a deduction of the relationship

between the density of medium and the

refractive index.

[ 5 marks ]



(c) With the aid of ray diagram, explain how a

man shoots a fish in water so that he hits the

target.

[ 3 marks ]

(d) (i) You are given two pieces identical

prism with internal angle 45o

, 900

and

450

and two converging lenses to make

a binocular.

Using the material stated above, explain

how you are going to build a simple

binocular.

[ 6 marks ]

(ii) Suggest modifications need to be done

on the simple binocular to produce

brighter and bigger image.

[ 4 marks ]

CHAPTER 6

22. Diagram 10.1 and 10.2 show wave pattern

produced by the vibration of two spherical dippers

on the water surface set to be at different distances.

Diagram 10.1

Diagram 10.2

(a) (i) What is the wave phenomenon shown in

diagram 10.1 and 10.2?

[ 1 mark ]

(ii) Explain why the water level in the ripple

tank must be at constant depth during the

experiment.

[ 4 marks ]

(iii) Observe Figure 10.1 and 10.2. Compare

the wave patterns produced by the

spherical dippers. State the relationship

between the distance of two coherent

sources and the separation / distanceof

two consecutive nodes or antinodes

lines.

[ 10 marks ]

(b) Sonar technique can be used to determine the

distance between two positions. Ultrasonic

wave is used in this technique.

(i) What is sonar?

[ 1 mark ]

(ii) Explain why using ultrasonic wave is

better than just ordinary sound waves.

[ 2 marks ]

(iii) A marine researcher wants to use

ultrasonic sound to determine the depth

of the ocean bed. Explain how he can do

so.

[ 7 marks ]

23. Diagram 12.1 shows the pattern of sea waves when

approaching the beach.

Diagram 12.1

(i) Name the wave phenomenon shown in

Diagram 12.1.

[1 mark]

(ii) Explain in terms of the wave phenomena in 12

(a)(i), why the water waves follow the shape

of the beach as it approaches the shore.

[4 marks]



(b) The beach in Diagram 12.1 will be used as a

place where fisherman boats are kept.

You are assigned to investigate the design for the

location to keep the boats and the characteristics of

the retaining wall as shown in Diagram 12.2 based

on the following aspects:

- the location to keep the boat

- material used for the retaining wall

- the height of retaining wall

- size of slit

Explain the suitability of the location and the

characteristics of the retaining wall and determine

the most suitable design to keep the boat safely.

[10 marks]

(c) Diagram 12.3 show a pattern of wave formed

when the water waves with a speed of 6 cm s-1

propagates from a deeper area to a shallow

region in a ripple tank.

Deep area Shallow area

λ = 0.8 cm λ = 0.5 cm

Diagram 12.3

Calculate:

(i) the frequency of water waves at the

deeper region

(ii) the speed of the water waves at shallow

region.

[5 marks]

24. A student carries out an experiment to investigate a

water wave phenomenon using a ripple tank.

Diagram 10.1 and Diagram 10.2 show the pattern

obtained on the screen of the ripple tank when two

vibrators, S and T, are vibrating simultaneously.

Diagram 10.1



Diagram 10.2

(a) (i) State the reason why the depth of water

in the ripple tank must be uniform.

[1 mark]

(ii) Name the water wave phenomenon that

is being investigated.

[1 mark]

(iii) State the amplitude of the wave along the

nodal lines.

[1 mark]

(iv) Using a suitable diagram, explain how a

nodal line is formed.

[2 marks]

(b) Observe Diagram 10.1 and Diagram 10.2.

(i) Compare the distance between vibrators

S and T.

[1 mark]

(ii) Compare the distance between adjacent

nodal lines.

[1 mark]

(iii) Compare the wavelength of the water

waves.

[1 mark]

(iv) State the relationship between a and x.

[a = distance between the vibrators, x =

distance between adjacent lines]

[2 marks]

(c) Diagram 10.3 shows the plan of a football

stadium. When an announcement was made

using only one loudspeaker, spectators at

positions such as P, Q and R could not hear

the announcement clearly.

Diagram 10.3

Suggest and explain improvements to the

sound system and transmission of the sound

so that spectators all around the stadium can

hear the announcement clearly.

Your answer should cover the following

aspects:

(i) The number of loudspeakers

(ii) The position of the loudspeakers

(iii) The amplification of the sound

[6 marks]

(d) The loudspeaker used in (c) is as shown in

Diagram 10.4

Diagram 10.4

Explain whether D and L should be big or

small so that sound from the loudspeaker can

be transmitted over a longer distance.

[4 marks]



25. Diagram 10.1 and Diagram 10.2 show the pattern

of interference using coherent sources of water

waves.


(a) How does constructive interference occur?

[ 1 mark ]

(b) Using Diagram 10.1 and Diagram 10.2,

compare the distance between the two

coherent sources, wavelength of the

propagating water waves and distance

between two consecutive antinodes.

[ 4 marks ]

(c) Relate the distance between the two

coherent sources with the distance between

two consecutive antinodes.

[ 2 marks]

(d) Diagram 10.3 shows tourists at a beach

observing the sunset.

Diagram 10.3

Using physics concepts, explain why the

tourist can still able to see the sun even

though it has already set.

(e) Diagram 10.4 shows a restaurant in the town

of Seremban. The restaurant is always

packed with customers and always noisy. A

student and his parents often visit the

restaurant to enjoy a pleasant dinner. The

restaurant in Diagram 10.4 is not suitable for

a quiet evening and they decided to suggest

a few modifications to the restaurant owner.

Diagram10.4

Using the appropriate physics concepts,

suggest and explain the modifications that

have to be done to reduce the noise pollution.

The modifications should include the

following aspects:

(i) Materials used for floor, ceiling and wall.

(ii) Finishing for table and countertops.

(iii) Solution for large windows

(iv) Dining space design

[ 10 marks ]

26. Diagram 10.1 shows a tuning fork vibrating near a

microphone. The sound waves detected by the

microphone are displayed on the screen of a

Cathode -Ray Oscilloscope (CRO).

When the tuning fork is struck harder , sound

produced is louder and the sound waves produces

are shown in Diagram 10.2.


(a) What is the meaning of longitudinal wave?

[ 1 mark ]


(i) Compare the amplitude of vibrations of

tuning fork.

(ii) Compare the peak values a1 and a

2of the

waves displayed by the oscilloscope.

(iii) Relate the amplitude of vibrations of

tuning fork to the peak values.



(iv) Relate the peak values to the loudness

of the sound produced.

(v) Hence, deduce the relationship between

the loudness of the sound and the

amplitude of the wave.

[ 5 marks ]

(c) Explain how the sound wave is used to

determine the depth of an ocean.

[ 4 marks ]

(d) You have been assigned as a consultant to

assemble a speaker system to improve the

acoustics of a school hall. Using the

appropriate concept explain how the

installation of the speaker system and the

other modifications that can improve audible

sound. In your explanation , elaborate on the

following aspects:

(i) Distance between two stereo speakers.

(ii) Wall and floor finishing

(iii) Power of the loud speakers

(iv) Positioning of speakers and

microphones.

[ 10 marks ]

CHAPTER 7

27. Diagram 10.1 and Diagram 10.2 show two circuits.

Each circuit contains an ammeter, 4 cells, rheostat

and a filament lamp labeled 6V, 24 W. Diagram

10.3 and Diagram 10.4 show the thickness of

coiled wire of the filament lamp M and N,

respectively.


Filament lamp M Filament lamp N


(a) What is the meaning of the labeled “6V, 24

W” on the filament lamp?

[1 mark]

(b) (i) Observe Diagram 10.1and Diagram 10.2.

Compare the reading of the ammeter and the

brightness of the filament lamp M and N.

[2 marks]

(ii) Observe Diagram 10.3 and Diagram

10.4. Compare the thickness of coiled

wire of the filament lamps.

[1 mark]

(iii) Relate the brightness of the filament

lamp with the thickness of coiled wire

to make a deduction on the relationship

between thickness of coil wire and the

heat produced by the filament lamp

[2 marks]

(c) Diagram 10.5 shows two types of plug for the

electric kettle that can be connected to the

electric supply. Diagram 10.5(a) uses two pin

plug, while Diagram 10.5(b) uses a three pin

plug with an earth wire.

Diagram 10.5(a) Diagram 10.5(b)

Explain why a three pin plug is more

suitable compared with a two pins plug.

[4 marks]

(d) Diagram 10.6 shows a water heater used to

boil water.

Diagram 10.6

Using appropriate physics concepts, suggest

and explain how to build a water heater which

can boil a larger quantity of water faster ,



more efficient, and more safety based on the

following aspects;

(i) type of material used for the heating

element of the water heater

(ii) shape of the heating element of the

water heater

(iii) melting point of the heating element of

the water heater

(iv) rate of rusting of the heating element of

the water heater

(v) additional component used for safety

when the water boil

[10 marks]

28. Diagram 12.1 shows a hair dryer labelled 240 V,

500 W connected to a three pin plug.

Diagram 12.2 shows the fuse in the three pin plug.

Diagram 12.1

Diagram 12.2

(a) State two properties of the material of the heating

element in the hair dryer.

[4 marks]

(b) (i) What is the meaning of the label 0.5 A on the

fuse?

[1 mark]

(ii) Table 12 shows the specification of a few

metals to be used as a fuse wire.

Table 12

Explain the suitability of each characteristic of the

four metals and determine the most suitable metal

to be used as the fuse wire. Give

reasons for your choice.

[10 marks]

(c) The hair dryer is Diagram 12.1 is switched on.

(i) Calculate the current flowing through the hair

dryer.

(ii) State whether the 0.5 A fuse is suitable to be

used in the plug.

(iii) Calculate the energy used by the hair dryer

when it is switched on for 10 minutes.

[5 marks]

28. Diagram 12.1 shows a typical circuit on a

household electrical appliance that using a fuse.

Diagram 12.1

(a) What is a fuse?

[ 1 mark ]

(b) Explain the advantages o parallel circuit in a

house wiring system.

[ 4 marks ]

(c) An immersion heater its specifications of

240V , 500 W is used to boil water. The

efficiency of that immersion heater is 85.

(i) What is meant by 250 V, 500 W?

[ 1 mark ]



(ii) Calculate the electric current that passes

through the immersion heater.

[ 2 marks ]

(iii) Calculate the output power of the

immersion heater.

[ 2 marks ]

(d) Fuse takes some time to melt or blow. A fast-

blowing fuse is required to protect

semiconductor equipments which cannot

stand high current surge for too long. When a

fuse blows, sparking may occur and produces

high temperature. The fuse wire is placed in a

sheath or catridge as shown in Diagram 12.2

to prevent its sparks from causing damage.

Diagram 12.1

Table 12.1 shows the specifications of five

fuses tat can be used to protect a

semiconductor device.

Table 12.1

Determine the most suitable fuse to protect a

240V, 2000 W semiconductor material device.

Study the specifications of all five fuses based on


- The thickness of wire

- The rating of fuse

- The catridge type

- The melting point

Explain the suitability of the aspects and justify your

choice.

[ 10 marks ]

CHAPTER 8

29. Diagram 10.1 and Diagram 10.2 show two

identical electromagnets, X and Y. The current

flow in electromagnet X is 2 A and the current

flow in electromagnet Y is 3 A.


(a) What is the meaning of electromagnet ?

[1 mark]


compare the amount of iron filings attracted,

current flow and the magnetic field strength of

the two electromagnets.

Relate the current flow with the magnetic

field strength to make a deduction on the

relationship between magnetic field strength

and the amount of iron filings attracted in this

situation.

[5 marks]

(c) Diagram 10.3 shows an electromagnet crane.

Explain how the electromagnet crane can be used

to lift scrap metal.

[4 marks]

(d) A man needs an adaptor to charge his

handphone as shown in Diagram 10.4. The

transformer inside the adaptor is used to

reduce the 240 V alternating current (a.c) to

12 V direct current (d.c).



Using the knowledge of a transformer and

rectifier, suggest and explain how to built an

adaptor which can be used to charge the

handphone.

(i) The type of transformer

(ii) The ratio of number of turns in

primary coil to the number of turns in

secondary coil

(iii) The type of core

(iv) The electronic component that should

be connected to the output of the

secondary coil

(v) The material of wire used

[ 10 marks ]

30. Diagram 12.1 shows a simple transformer.

Diagram 12.1

(a) State the transformations of energy involved

in Diagram 12.1.

[ 1mark]

(b) Explain how the transformer works

[ 4 marks]

(c) You are asked to investigate the design and

the characteristic of four transformers shown

in Diagram 12.2.Explain the suitability of

each characteristics of the transformer and

determine the transformer which can be use as

an ideal transformer.


[10 marks]

(d) Diagram 12.3 shows a 12V, 48W bulb lights

up with normal brightness when it is

connected to a 240V main supply through a

transformer.

Calculate:

(i) the output voltage of the transformer

(ii) the number of turns of the primary coil

(iii) the efficiency of the transformer .



31. When a current flows through the solenoid it

produces a magnetic field and then becomes

electromagnet.

(a) What is a meaning of electromagnet ?

[ 1 mark ]

(b) Diagram 12.1 shows a graph of number of

paper clips attached, n against current, I, for

a solenoid.

Diagram 12.1

(i) Based on the graph, state the

relationships between n and I .

What can you conclude about the

strength of electromagnet?

[ 2marks]

(ii) State two physical quantities that affect

the strength of electromagnet?

[ 2marks]


the characteristics of four alternating current

generators shown in Table 12.1.


the alternating current generators and

determine the alternating current generator

which can supply a large direct current to an

electrical component S shown in Diagram

12.2.

Diagram 12.2

(d) Diagram 12.3 shows a model for transmission

of electrical power. The resistance of the

transmission cable in the model is 30Ω.

Diagram 12.3

(i) Name a type of conductor that is most

suitable to be used as transmission cable.

[ 1 mark ]

(ii) Calculate the current that flows

through the transmission cable

[ 2 marks ]

(iii) The power loss due to heating effect

of the transmission cable

[ 2 marks ]



32. Diagram 12.1 shows a bulb labelled 12 V, 24 W is

connected to the output of a transformer. The

efficiency of the transformer is 40%.

(a) (i) Name the type of transformer.

[1 mark]

(ii) Explain the working principle of the

transformer.

[4 marks]

(b) Calculate

(i) the current flow in the secondary coil.

(ii) power input in the primary coil.

[5 marks]


the characteristics of four transformers

shown in Diagram 12.2.


the transformers and determine which transformer

has the highest efficiency.

Give reasons for your choice

[10 marks]

33. Diagram 10.1 and Diagram 10.2 show how

induced current are produced in solenoids

(a) What is meant by induced current?

(b) Using Diagram 10.1 and 10.2,

compare

(i) The number of turns of the

solenoid.

(ii) The deflection of the

galvanometer pointer.

(iii) The rate of cutting of the

magnetic flux.

(iv) The magnitude of induced

current produced.

[ 4 marks ]

(c) Using Diagram 10.1 and 10.2

(i) Relate the number of turns of the

solenoid and the rate of cutting of

the magnetic flux.

(ii) Relate the rate of cutting of

magnetic flux and the

magnitude of the induced current

produced and hence.

[ 2 marks ]

(d) Name the physics law involved.

[ 1 mark]



(e) Diagram 10.3 shows a simple step-up

transformer

(i) Explain why step-up

transformers are used in the

transmission of electricity?

[ 2 marks ]

(ii) You are required to modify the

transformer in Diagram 10.3 so

that it can use as an efficient

laptop adapter with output of

18.5 V of direct current. Your

suggestions and explanation

should be based on the

following aspects:

- Type of the core used.

- materials and diameter of the

wire used.

- Ratio of the number of turns

in the primary coil to the

secondary coil.

- The arrangement of the

primary coil and the secondary

coil.

- The numbers of diodes used.

[ 10 marks ]

34. Diagram 10.1 shows one insulated conductor

which is moved downwards in a magnetic field.

Diagram 1.2 shows three insulated conductors

which are moved downwards in the magnetic field.

(a) What is meant by electromagnetic

induction?

[ 1 mark ]

(b) Using Diagram 10.1 and Diagram 10.2 ,

compare

(i) The number of conductor wires.

[ 1 mark ]

(ii) The deflection of the galvanometer

pointer.

[ 1 mark ]

(iii) Relate the number of conductor and

the rate of cutting of magnetic flux.

[ 1 mark ]

(iv) Relate the rate of cutting of magnetic

flux and the induced current

[ 1 mark ]

(v) Name the physics law involved.

[ 1 mark ]

(c) Diagram 10.3 shows the structure of a

generator. Explain how the generator can e

used to produce electricity.

[ 4 marks ]

(d) Diagram 10.4 shows the cross section of a

moving coil microphone which converts one

form energy into another.

When sound vibrates the diaphragm , the

attached voice coil moves and cut the



magnetic field and generates a small electric

current in coil.

Using the appropriate concepts in physics ,

suggest and explain suitable modification or

ways to enable the microphone to detect

sound effectively and generate bigger

current based on the following aspects:

(i) The thickness of diaphragm

(ii) The strength of the material for the

diaphragm

(iii) The number of turns of coil

(iv) The diameter of the coil wire

(v) The strength of magnet

[ 10 marks ]

35. (a) Diagram 10.1 and Diagram 10.2 shows two

identical electromagnet, X and Y .


(i) What is meant by electromagnet?

[ 1 mark ]

(ii) Using Diagram 10.1 and Diagram 10.2

compare the current flow, the amount of iron

filing and the magnetic field strength of the

two electrodes. Relate the current flow and

amount of iron filing attracted by the

electromagnet and the magnetic field

strength..

[ 5 marks ]

(b) Diagram 10.3 shows a circuit breaker.

Diagram 10.3

Explain how the circuit breaker works.

[ 4 marks]

(c) Diagram 10.4 shows an a.c generator

Diagram10.4

(i) Explain how the generator works to

produce alternating current..

[ 4 marks ]

(ii) Explain the modification that needs to

be done on the generator and the

external circuit to enable the generator

to be a d.c generator and produce

more current.

[6 marks]



CHAPTER 9

36. As a research engineer in a factory, you are asked

to investigate the characteristics of several

substances in order to produce semiconductors

with better conductivity.

(a) What is meant by semiconductor?

[1 mark]

(b) Name two types of semiconductors. Explain

the differences between this two types of

semiconductors

[5 marks]

(c) Table 12 shows the characteristics of five

substances P, Q, R, S and T.

Table 12

Explain the suitability of the characteristics of the

substances to be used in the production of a

semiconductor with better conductivity and

determine the most suitable substance to be used


[10 marks]

(d) An extra high voltage (EHT) supply gives 4

kV across the anode and the cathode of a

vacuum tube.

(i) Name the process that occurs.

[1 mark]

(ii) Calculate the velocity of the electron

when it reaches the anode tube. [ mass

of electron , m = 9.1 x 10-31

kg, charge

of electron, e = 1.6 x 10-19

[3 marks]

37. A semiconductor diode is an electronic device

made by joining pieces of p-type and n-type

semiconductors. n-type and p- type

semiconductors are produced through the doping

process


(a) What is the meaning of doping?

[1 mark]

(b) Using Diagram 10.1 and Diagram 10.2 ,

compare the connection of diode to the dry

cell, the lighting of bulbs and the reading of

ammeter. Relate the lighting of bulbs with

the connection of diode to the dry cell to

make a deduction regarding the relation

between the current flowing in the circuits

and the connection of diode to the dry cell..

[5 marks]

(c) Box Y contains four identical electronics

component for full wave rectification.

Diagram 10.3

On Diagram 10.3 draw the electronic

components in the circles provided.

(ii) A capacitor is placed across the output

to smooth the current. In Diagram

10.3, draw the wave form produced .



Explain how a capacitor is used to

smooth the current.

[4 marks]

(d) Diagram 10.4 shows a circuit with a

transistor that acts as an automatic switch.

LED will light up when it is dark.

Diagram 10.4

A technician wants three fans labelled 240

V, 100 W in a room to be automatically

switched on when the room is hot.

Suggest modifications that can be made to

the circuit in Diagram 10.4 so that the three

fans can be automatically switched on when

the room is hot based on the following

aspect:

State and explain the modifications based on


- The electric component to replace

light dependent resistor in the circuit.

- The position of electric component.

- he used of relay switch in the circuit..

- the arrangement of the three fan.

- electric component to protect the

transistor

[10 marks]

38. Diagram 10.1 shows a transistor circuit. Diagram

10.2 and Diagram 10.3 show the transistor circuit

with different microammeter reading

and milliammeter reading.

Diagram 10.1

Diagram 10.2

Diaragm 10.3

(a) What is the meaning of transistor circuit?

[1 mark]



(b) (i) Using Diagram 10.1, compare the

microammeter reading and the

milliammeter reading.

(ii) Using Diagram 10.2, compare the

microammeter

reading and the milliammeter reading.

(iii) Using Diagram 10.2 and Diagram

10.3, compare the change in

microammeter reading and the change

in milliammeter reading.

(iv) Relate the microammeter reading,

milliammeter\ reading and deduce a

physics concept for base current , Ib

and collector current, I

c in a transistor

circuit.

[5 marks]

(c) Diagram 10.5 shows a transistor circuit is

used to light up a bulb at night.

Diagram 10.5

Explain why the bulb light up at night.

[4 marks]

(d) Suggest the modifications need to be done to

the circuit in Diagram 10.5 so that it can

function as automatically fire alarm switch

that needs high voltage.

Explain your suggestions base on the

following aspects:

(i) The electrical components that are

needed to replace any components in

the circuit

(ii) The position of these components in

the circuit

(iii) The electrical components that is

connected to the output transistor

[10 marks]

39. (a) What is meant by a semiconductor?

[ 1 mark]

(b) Diagram 12.1 shows a full wave rectifier

circuit.

Diagram 12.1

(i) Draw the waveform of a full wave

rectification.

[ 1 mark ]

(ii) What modification can do on the

circuit in Diagram 12.1 to smooth the

current?

[ 1 mark ]

(iii) Draw on Diagram 12.1 the

modification you suggest in (a)(ii).

[ 1 mark ]

(iv) Draw the smoothen current.

[ 1 mark ]

(d) The door of the lift is fitted with a light

transmitter and a detector which is a light

dependent resistor (LDR). If the LDR

detects light, the relay switch is activated

and the lift door will close.You are asked to

investigate the circuit of the lift, and design

suitable circuit to close the door of the lift, if

there is no people in front of the lift as

shown in Table 12.



Table 12

Explain the suitability of the characteristics in

Table 12 and than determine the most suitable

circuit for the door of the lift. Give a reason for

your choice.

[ 10 marks ]

(d) Diagram 12.2 shows trace of CRO screen

when a potential different connected on it.

The Y- gain setting is 2 V / div and time-

base is set to 0.1s / div.

Diagram 12.2

(i) What type of current that is connected

to the CRO?

[ 1 mark ]

(ii) What is the peak-voltage of the c

urrent?

[ 1 mark ]

(iii) Calculate the frequency of the current.

[ 2 marks ]

(e) Sketch the trace of CRO screen of the same

current if the time-base is off

[ 1 mark ]

CHAPTER 10

40. Radioisotopes can be used as tracers to detect leaks

from pipes underground. Diagram 12.1 shows a

leak that occurred in an underground water pipe.

Diagram 12.1

(a) What is meant by radioisotopes?

[ 1 mark ]

(b) With the aid of diagram, explain how

radioisotopes can be used to detect the

location of the leakage as shown in Diagram

12.1.

[ 3 marks ]



(c) Table 12.1 shows the characteristics of five

radioisotopes.

Table 12.1

Explain the suitability of each characteristic of the

radioisotope and determine the most suitable

radioisotope to be used in detecting the leak from

pipes underground.


[ 8 marks ]

(d) Diagram 12.2 shows the decay chain of

Radon-222.

(i) What is the number of neutrons in Rn-

222?

[ 1 mark ]

(ii) Write an equation to show the decay

of Rn-222 to Po-218.

[ 2 marks ]

(iii) Determine the number of alpha

particles and beta particles produced

in the decay.

[ 2 marks ]

(e) A lab assistant measures the number of

particles emitted per minute from two

different radioactive sources K and L. The

measurements are repeated each hour for

four hours and the results are shown in

Table 12.2.

Table 12.2

(i) Name the source that has the shortest

half-life?

[ 1 mark ]

(ii) The experiment continues until the

time is 6 hours.

Calculate the number of particles

emitted per minute from source K.

[ 2 marks]

41. Diagram 12.1 shows a Geiger Muller tube (GM

tube) an a rate meter which are used to detect

radioactive radiation.

Diagram 12.1

(a) What is meant by radioactivity?

[ 1 mark ]

(b) Explain how the GM tube is able to detect

the radioactive radiation.

[ 4 marks ]

(c) Radioactive material is also used in smoke

detectors. You are assigned to study the

characteristics of some radioactive materials

and the type of logic gates used in the smoke

detector shown in Table 12.1.



Table 12.1

[ 10 marks ]

(d) (i) Copy and complete the equation for

the radioactive decay shows below by

writing the appropriate numbers in

box provided.

(ii) Calculate the mass defect in kg.

[ 2 marks ]

(iii) Calculate the energy released.

[ 2 marks ]

42. (a) Diagram 12.1 shows a system used in a

factory to ensure the volume of guava juice

in a bottle is uniform.

The radioactive source, radiation detector

and counter are used to detect the volume

of guava juice. The radioactive source

contains a radioisotope.

(a) What is meant by a radioisotope?

[1 mark]

(b) Table 12.2 shows the characteristics of five

radioisotopes P, Q, R, S and T.

As a factory engineer, you are required to

determine the most suitable radioisotope that

can be used by the system to ensure the volume of

guava juice is uniform.

Study the characteristics of all 5 radioisotopes and

explain the suitability of the aspects.

Determine the most suitable radioisotope and give

the reason for your choice.

[10 marks]

(c) Table 12.3 shows the reading of the rate

meter for 6 bottles through detector and

radioactive source .

(i) State one detector that is suitable to be

used purpose.

[ 1 mark]



(ii) Based on table 12.3, which bottle

shows the least volume of juice and

state the reason for your answer.

[3 marks]

(d) In a radioactive decay series, Uranium-238

decays to become Radium-226 by emitting

alfa and beta.

Determine the values of X and Y?

[5 marks]

-END-

CHAPTER 2

Question No. 1

(a)(i) The object falling under the force of gravity only

(a)(ii) The acceleration Diagram 9.1 larger than Diagram 9.2

The rate change Diagram 9.1 more than Diagram 9.2 The time

impact Diagram 9.1 more than Diagram 9.2

When the time impact is smaller, the rate change of

momentum

When the acceleration is large, the rate change of momentum

is large is large

(b) (i)

(ii) The force forward = friction

The resultant force is zero

The object move with constant velocity

(c)

Question No. 2

(a) Mass is the amount of matter in an object.

(b)

(c) (i) The inertia of the driver maintains the forward motion

when the car stops suddenly.

(ii) Wearing a seat belt:

Restrains the body of the driver from being thrown

forward//inside or outside the car.

It slows down the forward movement of the driver when

the car stops suddenly

(d)

Design or

way

Explanation/reason

Acceleration Smaller mass The smaller the mass the smaller its

inertia. Therefore the rocket will

accelerate faster.

Shape Nose cone //

Bullet shape

on top of the

body

To improve the aerodynamics of the

rocket.

Structure The bottle

filled with

mixture of

water and air

Serves as the propulsion of the water

rocket//The air pressure propels the

rocket skyward (upward)

Buoyant force

(upthrust)

Equipped

with

parachute

The parachute increases the surface

area of an object so it has more

contact with the wind, which

decreases the speed of the object

(due to air resistant)

Stability of the

motion

Fitted with

fins spaced

equally

around the

rocket body.

Helps to stabilize the water rocket by

lowering the centre of pressure

(gravity)

Question No. 3

(a) The Principle of Conservation of Momentum / Energy

(b) When the ball on one end is pulled up and let to fall, it strikes

the second ball which is at rest and comes to a dead stop.

The momentum of the ball becomes zero as its velocity is zero.

The Principle of Conservation of Momentum states that in a

collision between two objects the total momentum of the objects

in the system remains unchanged.

The energy and momentum from the first ball is transferred to

the second ball and then transmitted through the balls at rest to

the ball on the other end.

Because the momentum and energy is maintained in this system,

the ball on the opposite side will move at the same velocity as

the ball that were in initial motion

(c)

The balls touch each

other

This will reduce losses of energy which

will reduce the speed of the balls

The type of material

used to make the balls is

steel

Steel balls are hard and produce highly

elastic collision. Energy can easily

propagates through the intermediate

balls.

Two strings used to

hang each ball

This string arrangement restricts the

balls’ movements to the same plane.

the position of the ball

to start the oscillation

High position of the ball, high potential

energy and will change to high kinetic

energy. The last end ball will swing at

bigger speed.

The most suitable design is Q because the ball s touch each other,

made from steel, use two strings attached to each ball and the initial

position of the ball is high.

(d) (i) m1u1+ m2u2= m1v1 + m2v2

(5)(0.8) + (3)(0) = 0 + (3) v2

v2 = 1.33 ms-1

(ii) m1v1 - m2u2 = 0 – (0.05)(0.8)

= -0.04 kgms-1

(iii) Impulsive force = -0.04 / 0.05 = 0.8 N

modification reason

The surface is smooth Reduce water resistance

Aerodynamic Reduce friction

Low density Lighter

Big peddle Increases the force

strong Not easy to broke down

Lorry Car

Mass Mass of the

lorry is bigger.

Mass of the

car is smaller.

Ability

to speed

ahead

Takes longer

time to speed

ahead.

Easier//faster

to speed

ahead.

Stopping

(from

rest)

Harder//slower

to stop moving.

Takes longer

time to stop

moving.

Easier//faster

to stop

moving.

Takes shorter

time to stop

moving.

Question No. 4

(a) (i) Energy due to height

(ii) Initial position of the student in Diagram 9.1 is higher

The speed of the student on reaching the final position in

Diagram 9.1 is higher

The higher the speed of the student, the higher the energy

The higher the position , the higher the energy gained

(iii) Principle of Conservation of Energy

(b) (i) elastic potential energy to kinetic energy and

gravitational potential energy

elastic potential energy and kinetic energy to

gravitational potential energy

(ii) due to damping

work done against air resistance //

loss of energy due to the extension and compression of

the molecules in the system

(c) strong // high strength

it won’t break easily

high force constant

store higher elastic potential energy

strong // high strength // any suitable material

it won’t break easily

thin // aerodynamic // streamline

less air resistance

slightly above the target

the path is parabolic / curved/downward // due to free fall

motion

Question No. 5

(a) (i) Priciple of conservation of momentum

(ii) Air expels at high velocity

Produces momentum backwards / to the left

Causes thrust of momentum forward/ to the right

With same magnitude of force but in opposite direction

(b) (i)

(ii) a = v – u

t

= 0 – 4

2

= 2 ms-2

(iii) s = )2()4(

2

1 2

= 16 m

(c)

Characteristics Reasons

Shape – Inverted aerofoil High pressure at top // greater

downward force//high stability

Ridges on tyres -none Less friction during motion

Engine power -high Greater forward thrust

Material light and stiff Does not break easily on impact

I choose S

Because shape – inverted aerofoil , ridges on tyres –none, engine

power –high and material light and stiff

CHAPTER 3

Question No. 6

(a) (i) Sum of two or more forces to produce one resultant force.

(ii)

1. Bottle in liquid Q floats lower

2. Weight and the buoyant force are equal and the same in

both cases.

3. Density of liquid P is higher.

4. As the density of liquid decreases, the lower the bottle

floats.

5. When density of liquid decreases the volume of liquid

displaced increases to produce the same buoyant force.

(b)

1. When force is applied to piston A

2. Pressure is produced and transmitted uniformly throughout

the liquid towards piston B // Pascal’s Principle

3. Pressure multiply by the surface area of piston B will

produce the output force that lift load M.

4. Cross-sectional area of piston A is smaller than piston B to

produce large output force.

(c)

Suggestion Reasons

Fix a long handle on

piston A

Small force can produce

bigger force /torque to press

piston A

Equip the hydraulic jack

with valves

Liquid can flow in one

direction and does not back

flow

Use released valves Liquid flows back to the

storage reservoir

Piston A is made

smaller // piston B

bigger.

To produce large output

force.

Oil as liquid Does not evaporate easily //

does not flow out easily//

prevent from rust.

Question No. 7

(a) (i) Force per unit area

(ii) Pressure on piston Q = pressure on piston R

Cross sectional area of piston Q < Cross sectional area of

piston R

Force acted on piston Q < force acted on piston R

The greater the area, the greater the force

Pascal’s principle

(b) aerofoil shape

The air speed on the upper surface > the air speed on the lower

surface.

The pressure on the lower surface > pressure on the upper

surface.

Different in pressure produce lift force.

(c)

Design Reasons

Thick wall Water pressure increase with

depth

High density material Increase mass / can submerge

easily

Strong material Does not break easily

Aerodynamic shape Reduce water resistance

Ballast tank To increase or reduce weight

Sonar transmitter and

receiver To estimate distance and depth

Question No. 8

(a) Upwards force cause by weight of fluid displaced by an object

when the object is immerse in the fluid.

(b) Valve release air from ballast tank.

Sea water flooded ballast tank

The weight of water displaced is smaller.

Buoyant force < Weight of the submarine

(c)

Choices Reasons

The volume of ballast

tank is higher

To produce bigger buoyant force

/ easy to rise up / can carry

greater weight inside

More number of air

tanks cylinder carried

Can stay longer time under the

water / Can rise and submerge

many times / more air supply for

respiration of crews

Can withstand higher

maximum water

pressure

Safe when the submarine

submerge very deep in the sea /

The body will not break due to

high water pressure

The suitable shape of

submarine is

aerodynamic

Less water resistance in the

motion / can move faster

Submarine X

Because the volume of ballast tank is higher, more number of

air tanks cylinder carried, can withstand higher maximum water

pressure and the suitable shape of submarine is aerodynamic.

(d) (i) V = 0.2 x 0.8

= 0.16 m3

(ii) B = Vρg = 0.16 x 1000 x 10

= 1600N

(iii) mass = 1600 ÷ 10 = 160 kg

Question No. 9

(a) Aerofoil

(b) (i) The shape of cross section of the wing causes the speed

of airflow above the wings to be higher than the speed of

airflow below.

When the speed of moving air is higher the pressure is

lower.

Hence air pressure below the wings is higher compare to

above the wings.

(ii) Bernoulli’s Principle

(c)

The most suitable wing is Y.

Because it has a shape of cross section which is upper side is

longer than the bottom, large the area of the wing, the low

density of the wing materials and the high the difference in

speed of air.

(d) (i) P=F/A

F = 400 x 50

F = 20000 N

(ii) Resultant Force = 20 000 – 900(10)

= 11000 N

Direction of force : upwards

Question No. 10

(a) (i) Buoyant force equal to weight of fluid displaced

(ii) Volume of air displaced equal to volume of a

balloon

Density of air decreased as a altitude increase

Weight of displaced air become smaller

At certain height weight of displaced air equal to

weight of the balloon

(iii)

Large balloon

To produce bigger buoyant / up thrust // Increase the

volume of the air displaced

Low density of gas filled in the balloon

Lighter

Synthetic nylon

Light-weight, strong and air-proof material

Low mass of radiosonde instrument

To produce a bigger upward resultan force

R is choosen

Large ballon/low density of gas /synthetic nylon /

low mass of radiosonde instrument

(b) (i) mass = density x volume

m=0.216kg

(ii) V= 1.2m3

m= 1.56kg

= 15.6N

Question No. 11

(a) (i) Buoyant force equal to weight of fluid displaced

(ii) Volume of air displaced equal to volume of a

balloon

Density of air decreased as a altitude increase

Weight of displaced air become smaller

At certain height weight of displaced air equal to

weight of the balloon

(iii)

Characteristics Explaination

Large ballon To produce bigger buoyant /

upthrust // Increase the

volume of the air displaced

Use 2 burners // Many

burners

To produce bigger flame //

heat up the gas in the

balloon faster

Synthetic nylon Light-weight/ strong /air-

proof material

High temperature of

the air in the balloon

Reduce the density /weight

of the air in the balloon

Hot air balloon Q is

chosen

Large balloon, use 2 burners

/ many burners, use

synthetic nylon and has high

temperature of the air in the

balloon.

(b) (i) mass = density x volume

m=0.216kg

(ii) V= 1.2m3

m= 1.56kg

= 15.6N

CHAPTER 4

Question No. 12

(a) (i) The temperature in which a solid substance change to

liquid at atmospheric pressure

(ii) The mass of substance in Diagram 9.1 < in Diagram 9.2

Time taken to reach the melting point in Diagram 9.1 <

in Diagram 9.2

Time taken by the substance to change into liquid

completely in Diagram 9.1 < in Diagram 9.2

The greater the mass the longer the time taken by the

substance to change into liquid completely.

The greater the mass the greater the latent heat of fusion

absorbed

(b) In daytime the sun warms the land to higher temperature than

the sea.

The land has a lower specific heat capacity than sea-water.

The air above the land is heated and rises

The cooler air above the sea moving to land.

(c)

Question No. 13

(a) The total amount of heat needed to increase the temperature of

an object by 1oC

(b) (i) 1. the temperature of water droplet = the temperature of

water poured on the hand

2. The mass of water droplets is smaller than water

poured

3. Hand in diagram 9.1 less injured than that in 9.2

4. the bigger the mass , the more injury to the skin

(ii) The bigger the mass of an object, the bigger the heat

capacity of the object

(c) Water has high specific heat capacity

When water in tube pass through the engine it can absorb large

amount of heat energy

Once water reach the radiator, the heat of the water absorbed by

the fin blade of the radiator .

The same time the fan in the radiator push the heat out of the

car.

(d) Thermometer is made from- transparent glass that is strong

so that it is not easily broken

The thermometric liquid- chosen is mercury uniformly /

opaque

because it easily expands

The capillary tube is made- narrow and thin

so that it is more sensitive

the shape of the thermometer- is round effect

so that it has a magnifying

high boiling point and low freezing point

so that it can measure very high and low temperature

CHAPTER 5

Question No. 14

(a) (i) Cannot be shown on screen

(ii) Incident ray from the fish refracted / change direction at

B.

Refraction

Incident ray from the dragon-fly reflected by water

surface at A.

(b) (i) Reflectionθ = 90o – 30o

= 60o

1.33 = o40sin

sinα

α = 58.75o

(ii) Virtual / same size / same distance / laterally inverted

(c)

Characteristics Explanation

Concave mirror Reflected ray is converging

Bulb at principal focus Reflected ray form a

parallel beam

Batteries connected in series Produces larger current

Copper connecting wire Low resistance / large

current

Torchlight Q is chosen

because it has concave mirror, bulb at principal focus,

batteries connected in series and copper connecting wire

Question No. 15

(a) Distance between focal pint and the optical centre of a lens

(b) 1. The convex lens is aimed/focused to a distant object

(infinity)

2. The screen is adjusted until a sharp image is formed on the

screen

3. The distance between the screen and the lens is measured

4. Focal length = distance between the screen and the lens

(c)

(d) (i) 1 = 1 + 1

f u v

1 = 1 – 1

v 5 400

v = 5.063 cm

(ii) h2 = v2

h1 v1

h2 = 5.063

100 400

h2 = 1.27 cm

(iii) Real , inverted and diminished.

Aspect Explanation

High specific heat

capacity of liquid

Becomes hot faster

High boiling point of

liquid

Not easily change into

vapour

Low rate of rusting

material

Long lasting // not

easily rust

Strong material Not easily breaks

The size of the fan is

big

To blow large amount

of heat

Aspect Explanation

Longer focal

length

To produce real, inverted and

smaller image

High

magnification

Produce bigger image

Distance = fo

+ fe

Produce image at normal

adjustment // image at infinity

Bigger

diameter

More light can enter objective

lens // more brighter

J is chosen Longer focal length, higher

magnification, Distance

between two lenses = fo + fe

and bigger diameter

Question No. 16

(a) (i) Distance between optical centre and focal point

(ii) Lens in Diagram 11.1 is thinner

Focal length in Diagram 11.1 is longer

The thinner the lens the longer the focal length

The thinner the lens the higher the power of lens

(b) (i) 5

1

(ii)

1

60

10

600

2030

3020

−

×

= 60 cm (iii)

230

60

(c)

- Convex lens

- Image is real and inverted

- Convex lens

- Image is virtual and magnified

- Longer

- must have a lower power

- have the larger diameter

- produce the brighter image

S and Convex lens of objective lens, Convex lens of Eyepiece

lens, longer fo and larger diameter

Question No. 17

(a) angle of incidence when the angle of refraction is 90o

(b) (i)

n = csin

1

(ii) 41.8o // refractive index for glass is smaller

24.6o // critical angle for diamond is smaller

The smaller the critical angle, the easier total internal

reflection can occur

(c) (i)

n = o

o

30sin

42sin

n = 1.34

(ii)

1.34 = depthapparent

1

0.75 m

(d) high refractive index

total internal reflection easier to occur // smaller critical angle

thick

keep cool / cut off more light

low

cut off more heat // reduce transmission of heat

small

critical angle can be easily exceeded // total internal reflection

easier to occur

Q

High refractive index, thick, low thermal conductivity and

small angle θ

Question No. 18

(a) The distance from the primary focus to the optical center

type of lens is convex, percentage of light is high , focal length

is short and size is bigger

(b) It should be convex

The magnified image can be obtained

Percentage of light of the lenses should be high

The image would be brighter and clearer

Its focal length should be short

The power of lens will be high and can be focused at a short

distance

diameter of lens should be large

it is gives a bigger display

the most suitable brand is J

type of lens is convex, percentage of light is high , focal length

is short and size is bigger

(c) (i) 1/f = 1/v + 1/u

1/5 = ½ + 1/v

v = - 3.33cm

(ii) magnification = v/u

3.33/2

1.67 times

(d) The lens is directed to a distant object such as tree

The screen was adjusted behind the lens until a sharp image

Formed

the distance between the lens and the screen measured

The power of the lens are determined using 1/f

The shorter the focal length the more the power of lens.

Question No. 19

(a) (i) Real image is an image which can be formed / projected

on a screen.

(ii) object distance in 9.1 is shorter than 9.2

Size of image formed in 9.1 is bigger than in 9.2

Image distance in 9.1 is smaller /shorter

The shorter the object distance, the bigger the size of the

image formed

When the object distance is shorter, the magnification

scale is bigger.

(b)

(c)

Use higher power bulb Higher intensity of light / more light

produced.

The filament of the bulb is

at the focus point of the

concave mirror

The light ray focuses to one point.

More curvature Increase the intensity.

lens between f and 2f To produce real and enlarge / bigger

images.

Increase the distance /

further away the screen

Larger image produced

Question No. 20

(a) (i) Refraction

(ii) Object distance in Diagram 9.1 < 9.2

Image distance in Diagram 9.1 > 9.2

Size of image in Diagram 9.1 > 9.2

Power of lens is same

The shorter the object distance ,the greater the size of

image.

(b) (i)

(ii) Range greater than two focal length ( u ≥2f)

(c) (i)

Modification Reason

f ≤ u ≤ 2f Image magnified and real

Distance = f0 + fe Eyes are not strained// to get

normal adjustment microscope

25 cm

fo = 10 cm and fe= 20 cm First image is magnified

Position of the first

image < fe

Final image is magnified many

times

(ii) use less power// longer focal length of eye piece lens

Move the object nearer to the focal point (still in between

(1F and 2F)

Question No. 21

(a) (i) Distance from the optical centre to a focal point.

(ii) Lens K is thicker than lens J

Light ray is refracted more in lens K than lens J.

Focal length of lens K is shorter than lens J.

Therefore the thicker the lens, the greater the refraction

of light and with that the shorter the focal length of a lens

will be

(b) (i) As a magnifying glass.

(ii) Enlarge/magnified

Inverted/upside down

Virtual

(c) (i) Choose lens S as objective lens

Choose lens Q as eyepiece

Lens S is placed in front of lens Q

The two lenses are adjusted so that they are in normal

adjustment where distance between the two lenses is

equal to (fo + fe)

(ii)

Modification Explanation

1. Use low power

convex lens as the

objective lens.

- Magnification of telescope =

e

o

f

f,

∴ Low power lens has a longer

focal length, fo ↑, magnification ↑

2. Use high power

convex lens as the eye

lens

High power lens has a shorter

focal length, fe ↓, magnification

3.Use bigger diameter

of objective lens

More light permitted to enter the

telescope and a clearer image is

seen

Question No. 22

(a) (i) Refraction

(ii) Ratio of sin i / sin r // The ratio of speed of light in

vacuum relative to that speed through a medium

(b) Refractive index of the glass is higher.

The density of glass is higher

The angle of refraction of light ray in glass is shorter

The higher the density of medium, the smaller the angle of

refraction of light.

The higher the density of medium, the higher the refractive

index.

(c)

(d) (i)

(ii)

Modifications Reasons

Objective lens with

larger

diameter.

More light passes

through the lens

Eyepiece lens with

higher

power // Thicker

eyepiece lens

Act as a strong

magnifying glass

WAVES

Question No. 23

(a) (i) Interference of waves

(ii) wavelength depend on depth of water

increasing/decreasing of depth will cause the wave to

refract

refraction will increase/decrease the length of wavelength

the nodal/antinodal line will be affected

(iii) wavelength produce by the two spherical dipper in

diagram 10.1 is the same as in diagram 10.2

the distance between the two consecutive antinodes

is greater in diagram 10.1 than 10.2

the distance between the two consecutive nodes is

greater in diagram 10.1 than 10.2

increase in the distance between the two coherent

source will decrease the distance between the two

consecutive nodes or antinodes

(b) (i) sonar is a reflection from an ultrasonic waves. (ultrasonic

echoes)

ultrasonic wave has a higher frequency waves , it has

more energy so it can move further

it do not produce noise

(iii) attach ultrasonic transmitter to a ship

use a microphone receiver to detect ultrasonic pulses

direct the ultrasonic pulses from the transmitter to the

seabed

use microphone receiver to pick up the reflected pulses

from the seabed

measure the time taken by the pulses to travel to the

seabed and return

calculate the depth of the water using the formula

2

txvd =

Question No. 24

(a) (i) Refraction

(ii) wave move from deeper to shallow area

the wavelength decrease

the speed decrease

the direction of wave bends towards normal

(b)

(c) (i) f = v

λ

= 6

0.8

= 7.5 Hz

(ii) V = λ f

= 0.5 x 7.5

= 3.75 cm

Question No. 25

(a) (i) To ensure constant velocity of water wave / ripple.

(ii) Interference

(iii) Zero or minimum

(iv) zero // minimum // smaller than the original amplitude

(b) (i) The distance in Diagram 10.1 is higher

(ii) The distance in Diagram 10.1 is smaller

(iii) Same

(iv) The higher the a, the smaller the x // a inversely

Proportional

(c) (i) Increase the number of loudspeakers // use more

Loudspeakers

Characteristics Reason

Bay Wave is calmer

Concrete retaining

wall

Stronger/ /

lasting

High wall Prevent high

wave

Smaller opening/

aperture / slit of

retaining wall

Diffraction

obvious // low

wave energy

P At bay, concrete

retaining wall ,

high wall and

smaller slit

To produce louder sound // Sound transmitted covers a

bigger

(ii) Placed at all corners // different locations

Cover a bigger area // the spectators around the area can

hear clearly

(iii) High amplification

to produce louder sound // sound can travel further

Large/big

Less diffraction // spreading // sound travels straight

Large/big

Vibrates more air // produces louder sound

Question No. 26

(a) When two crests or two troughs meet each other to form

maximum amplitude

(b) (i) Distance between two coherent sources in Diagram 10.2

is bigger than diagram 10.1

(ii) The wavelength are the same

(iii) The distance between two adjacent antinodal lines in

diagram 10.2 is smaller than diagram 10.1

(c) As the distance between two coherent sources increases, the

distance between two adjacent antinodal lines decreases.

(d) Refraction of light ray

Light travels from less dense to a denser medium

towards the normal / bending closer.

In the observer eyes, the sun is still not setting as they can still

see the image from refraction.

(e)

Question No. 27

(a) A wave in which the vibration of particles in the medium is

parallel to the direction of propagation of the wave

(b) (i) The amplitude in Diagram 10.2 is higher

(ii) The peak value, a2 in Diagram 10.2 is higher

(iii) The higher the amplitude of vibration of tuning forks, the

higher the peak value

(iv) The higher the peak value, the louder the sound

(v) The higher the amplitude, the louder the sound

(c) - Use ultrasound

- Ultrasound is transmitted to the sea bed

- a receiver will then detect the reflected the reflected pulses

- the time taken by the pulse to travel to the seabed and return

to the receiver being recorded, t

- the depth of the sea can be calculated using the formula,

2

vtd =

(d)

Suggestions Reason

Loudspeakers are

positioned at quite a

distance away.

So that the distance

between consecutive

constructive /

destructive interference is

smaller.

The two main

loudspeakers are not

positioned opposite

to each other

To prevent multiple

reflections

Fix soft boards/

wooden/ materials

which are sound

absorbers

Reflection effects can be

reduced

Use thick carpet/

Wooden floor/

Rubber floor

To prevent echo

Assemble a high

power speaker

system

To produce a high

amplitude of sound wave

Assemble the

speaker at a high

place

Wide coverage // the

wave is not blocked

CHAPTER 7

Question No. 28

(a) Distance between focal pint and the optical centre of a lens

(b) 1. The convex lens is aimed/focused to a distant object

(infinity)

2. The screen is adjusted until a sharp image is formed on the

screen

3. The distance between the screen and the lens is measured

4. Focal length = distance between the screen and the lens

(c)

(d) (i)

1 = 1 + 1

f u v

1 = 1 – 1

v 5 400

v = 5.063 cm

(ii)

h2 = v2

h1 v1

h2 = 5.063

100 400

h2 = 1.27 cm

(iii) Real , inverted and diminished.

Aspect Explanation

Longer focal

length

To produce real, inverted and

smaller image

High

magnification

Produce bigger image

Distance = fo + fe Produce image at normal

adjustment // image at infinity

Bigger diameter More light can enter objective

lens // more brighter

J is chosen Longer focal length, higher

magnification, Distance between

two lenses = fo + fe and bigger

diameter

Question No. 29

(a) High melting point

Can withstand high temperature / heat // does not melt easily

Not easily oxidized

Can last longer

(b) (i) Maximum current flowing through the fuse is 0.5 A

(ii) 1 Low melting point

2 Can melt easily

3 Low specific heat capacity

4 Can heat up easily

5 Small

6 High resistance // more heat released // easy to break

7 High

8 High resistance // more heat released

9 Z

10 Low melting point, low specific heat capacity, small

diameter and high resistivity

(c) (i) 240

500

= 2.08 A

(ii) Not suitable

(iii) 500 x (10x60)

300 000 J

Question No. 30

(a) A fuse is a very thin wire, which either melts or vaporizes when

too much current flows through it

(b) - A parallel circuit can run several devices using the full

voltage of the supply.

- If one device fails, the others will continue running normally

- If the device shorts, the other devices will receive no voltage,

preventing overload damage.

- A failure of one component does not lead to the failure of the

other components.

- More components may be added in parallel without the need

for more voltage.

- Each electrical appliance in the circuit has it own switch.

(c) (i) The electrical appliance use 240 V of voltage to generates

500 W of power.

(ii) Current = Power/Voltage

Current = 500/240 = 2.08 A

(iii) Efficiency = Output Power x 100 %

Input Power

Output Power = 85 x 500

100

Output power = 425 W

(d)


Thin fuse wire Less space needed/ to carry a limited

electrical current/ less mass hence low

heat capacity/ shorter time to heat up to

melting point and blow.

Ceramic cartridge Can withstand higher temperature

because sparks created by high voltage,

240V can be huge/

Fuse rating is 13 A Maximum rating must be higher than

normal current.

Low melting point For fast blow/ Melting faster when

excessive current flow/ Easy to cut the

current flow.

R is chosen because Because it has thin fuse wire, ceramic

cartridge, fuse rating is 13 A and low

melting point.

CHAPTER 8

Question No. 31

(a) An electromagnet is a coil wrapped around a soft iron core

which will be magnetized when a current flows through the coil

and demagnetized when the current is switched off

(b) Amount of iron filings attracted in Diagram 10.1 is smaller /

less// amount of iron filings attracted in Diagram 10.2 is higher

/ more

Current flow in Diagram 10.1 is smaller / less

// current flow in Diagram 10.2 is higher / more

Magnetic field strength in Diagram 10.1 is weaker

// Magnetic field strength in Diagram 10.2 is stronger

When the current is higher, the magnetic field strength is

stronger, or vice versa

When the magnetic field strength is stronger, the amount of

iron filings attracted is more, or vice versa

(c) When current flow through the solenoid, a magnetic field is

produced

The (soft) iron core will be magnetized

The scrap metal attracted to the iron core

When the current is switched off, the soft iron core will be

demagnetised and the scrap metal falls down

(d) Transformer step down

To reduce the voltage from 240 V to 12 V

The ratio of number of turns in primary coil to the number of

turns in secondary coil is 240 : 12 // 20 : 1

To reduce the voltage from 240 V to 12 V

Type of core is soft iron core // laminated iron core

Soft iron core is easy to magnetized and demagnetized //

Laminated iron core to reduce eddy current

Diode is connected to the output

To convert alternating current output to direct current

Use copper wire

Good electrical conductor // has low resistance // produce low

heat

Question No. 32

(a) Electrical energy light energy

(b) (i) 1. When an a.c. voltage is supplied to the primary coil,

the soft - iron core is magnetized

2. The magnet produced varies in magnitude and

direction

3. This causes a changing magnetic flux to pass through

the secondary coil

4. Induced e.m.f across the secondary coil is produced.

(c)

Aspect Explanation

Soft iron core Easy to magnetized and

demagnetised

Laminated Less eddy current/ reduce energy

lost

Thick wire

Reduce the resistance/more

current

Copper wire Low resistance/ reduce the lost of

heat

Q

Soft iron core, Laminated , thick

wire, Copper wire

(d) (i) 12 V

(ii) Np = 240 x 200 = 4000

12

(iii) Efficiency = Po x 100

Pi

= 240 x 0.2 x 100 = 100%

48

Question No. 33

(a) Magnet produce by current

(b) (i) Current, I directly proportional to the number of paper

clips attached, n The strength of electromagnet increases

(ii) The magnitude of the current / number of batteries (dry

cells)

The use of soft iron core

(c) High strength magnets

Larger force acting on the coil

High number of turns of coil

Larger force acting on the coil / higher electromagnetic

field strength

Low density material

Coil has smaller mass / lighter

Using 4 diodes and a capacitor

4 diodes to produce full-wave rectification and capacitor

as a smoother

Y and high number of turns of coil, low density, high

strength of magnets and 4 diodes and a capacitor.

(d) (i) Aluminium

(ii) 30

240

= 8

Ω

(iii)

30

240

= 1920 W

Question No. 34

(a) (i) Step-down

(ii) An alternating current flows through primary coil

The soft -iron core is magnetized.

The magnet produced varies in magnitude and direction.

This causes a changing magnetic flux to pass through the

secondary coil.

An induced e.m.f across the secondary coil is produced.

(b) I = 24/12

= 2A (with unit)

Efficiency = Output power x 100 %

Input power

= 24 x 100

40

= 60W

(c)

Characteristics Reasons

Thick

Soft iron

Laminated

Low//

near//shorter

Reduce the resistance of the coil

Reduce the hysteresis loss// can be magnetized

and demagnetized easily// Little energy used to

be magnetized and demagnetized .

Make the iron core as insulation.

Eddy current are not able to flow through the

layers of insulation// reduce eddy current

Reduce leakage of magnetic flux

Choose P because copper wire thick, soft iron core, laminated core

and distance is low.

Question No. 35

(a) (i) Current produced when the magnetic flux is cut by

conductor.

(b) (i) No. of turns of the solenoid in Diagram 10.2 is greater.

(ii) the deflection of the galvanometer pointer in Diagram

10.2 is bigger / larger.

(iii) the rate of cutting of the magnetic flux in Diagram 10.2

is greater.

(iv) Magnitude of induced current in Diagram10.2 is greater.

(c) (i) No of turns increases, rate of cutting of magnetic flux

increases.

(ii) Rate of cutting increases, magnitude of induced current

increases.

(d) Faraday’s Law

(e) (i) The greater the transmission voltage, the smaller the

current in the power lines.

Power loss during transmission due to resistance will be

smaller. / P=I2R

(ii)

1. laminated soft iron

core

2. to reduce the effect of

eddy current

3. thick copper wire 4. reduce heat loss due to

resistance

5. the ratio of turns in

primary coil to the

number of turns in

secondary coil is < 1

6. to reduce output voltage to

18.5 V

7. Wind the secondary

coil on top of the

primary coil

8. to reduce the leakage of

magnetic flux

9. 2/4 diodes 10. to produce full-wave

rectification

Question No. 36

Question No. 37

(a) (i) Electromagnet is a device in which magnetism is

produced by an electric current // temporary magnet

made by winding a coil round a soft iron core and

magnetic field produce when current flow.

(ii) Current flow in diagram 10.2 is more than 10.1 // vice

versa.

The amount of iron filing attracted by iron core in

Diagram 10.2 is more than 10.1 // vice versa.

The magnetic strength in diagram 10.2 is more than 10.1

// vice versa.

Amount of iron filing attracted increase when current

increase

The magnetic field strength increase when current

increase

(b) When too high current flow, magnetic field strength become

very strong / wire expand

electromagnet pull the soft iron armature / pulled to the right

by spring P.

release the catch, contact separate and current does not flow

When reset button is pressed, spring Q pulls the soft iron

armature back to its original position

(c) (i) When the coil rotates the coil cut across the magnetic

field lines

Induced current flow in the coil.

The current maximum when the coil cut the magnetic

field at right angle // current decreased (become zero)

when the coil move in parallel with magnetic field lines

The direction of current flow determine by using

Fleming’s right hand rule

After 90o the direction of current in the external circuit

reversed/ diagram

(ii)

Modification Explanation

Change slip rings with

commutator

To reverse contact with

brushes so that the current flow

in same direction in external

circuit

Use stronger magnet

To increase the magnetic field

strength

Use more number of turn for

the coil/ Increase the speed of

rotation

Increase the rate of change of

magnetic field/increase the

induced current

TOPIC 9

Question No. 38

(a) Semiconductors are a group of materials that can be conduct

electricity better than insulators but not as good as metal

conductors

(b) n- type semiconductor

p-type semiconductor

For n-type, majority charge-carries are electrons / minority

charge-carries are positive holes but for p-type, majority

charge-carries are positive holes / majority charge-carries are

electrons

For n-type, the doping substance is pentavalance but for p-type,

the doping substance is trivalance

(c)

Substance Q is chosen

Because Q has low resistivity at 00C, high melting point,

valency of the doping substance is 3 and the size of the doping

substance is almost the same as the size of the substance

(d) (i) Thermionic emission

(ii) Velocity of the electron, 2

2

1mveV =

31

19

101.9

4000106.12−

−

=x

xxxv

= 3.75 x 107 m s-1


The resistivity at 00C is

low

A current can flow through it

more easily//

Increasing the conductivity of the

substance

High melting point Not melting at high temperature

The valency of the

doping substance are 3

and 5

Valency of 3 is used to make p-

type semiconductor and valency

of 5 is used to make n-type

semiconductor

Size of the atom of the

doping substance is

almost the same as the

size of the substance

Can maintain the crystal-line

structure of the substance//

Give good effect in the doping

process

Question No. 39

(a) Doping is a process of adding a certain amount of specific

impurities to semiconductors to increase their conductivity

(b) Diagram 10.1, the p end of diode is connected to negative

terminal of dry cell // Diagram 10.2 the p end of diode is

connected to positive terminal of dry cell

Bulb in Diagram 10.1 does not lights up

No current flow in Diagram 10.1 // Current flow in Diagram

10.2

The bulb will lights up when the p end of diode is connected to

the positive terminal of dry cell // vice versa

Current only flow in the circuit when p end of diode is

connected to positive terminal of dry cell or in forward bias

(c) (i) Draw correct symbol and correct direction

(ii) Draw smooth waveform

Capasitors store charge when current flow

Capasitor discharge when current does not flow

(d) 1 LDR is replace by termistor / diagram

2 resistance decrease when temperature increase

3 Termistor is place at R1 and R1 replace LDR / diagram

4 So that V across R1 increase when the room is hot

5 Relay switch replace LED

6 To switch on secondary circuit /to switch on the fan

7 Fans are arranged parallel

8 All fans received 240 V power supply / other fans still

functioning even though one fan did not function

9 Resistor connected to the base of transistor

10 limit the current to the transistor

Question No. 40

(a) (i) Circuit consists transistor, resistor and cell

(ii) 10.1 : Microammeter no reading // 0 A,

milliammeter no reading // 0 A

(iii) 10.2 : Microammeter has a reading // 1 x 10-6 A ,

milliammeter has a reading // 1 x 10-3 A

(iv) Change in microammeter reading small, change in

milliammeter reading is bigger

Ib Increase, Ic increase // Ic depends on Ib

A small change in Ib caused a big change in Ic

(b) At night resistance LDR increases

VBE increases

Ib increases and switch on transistor

Ic increases and lights up bulb

(c)

Modification Explaination

Replace LDR with termistor To detect heat when temperature

is high

Replace bulb with siren / bell

To produce sound

Connect relay switch to output

transistor

To switch on the siren

Interchange the position of

resistor R and termistor

To increase base voltage / /

voltage across R // base current

Use 240 V power supply Siren is function at high voltage

Question No. 41

(a) Semiconductor is a material with electrical conductivity better

than an insulator but weaker than a conductor.

(b) (i)

(ii) connect a capacitor in parallel to the output

(iii)

(iv)

(c)

(d) (i) current a.c

(ii) 4V

(iii) T = 4 x 0.1 =0.4s

Frequency, f = 1/T

= 1/0.4

= 2.5 Hz

(iv)

Question No. 42

(a) Unstable isotopes which decay and emit radioactive particles /

ray

(b) Radioisotope is injected into the pipe

G-M tube as detector is used to find the leakage

Reading on detector increases when near a leakage

(c)

1. type of ray is

gamma

2. high penetration power

can penetrate through the

pipes

3. short half life 4. Decay faster and

detection can be done

faster

5. in liquid state 6. Easy to flow/ dissolve

(d) (i) 136

(ii)

(iii)

3 alpha

2 beta

(e) (i) Source L

(ii)

20 min-1

Question No. 43

Question No. 44

(a) Radioisotopes are isotopes which have unstable nuclei.

(b)

(c) (i) Geiger Muller Tube

(ii) Bottle E

Rate meter reading is the highest

Most radiation can reach the detector without being block

by juice

(d) Correctly stated that α as He4

2

Correctly stated that β as e0

1−

Working is shown

X = 3

Y = 2


Has a long half-life Can be used for a long

time hence save cost

Emits beta Can penetrate box and

liquid and is less

dangerous than gamma

Solid form Easy to handle and

contain.

Low ionising power Does not change the

state and taste of juice.

Radioisotope T It has long half life,

emits beta, in solid

form and has low

ionising power.

Physics p2 Essay

Documents

Transcript of Physics p2 Essay