:........................................................ Code: 5054 Class: CIIB

This document consists of 5 printed pages.

23 M

Test (Unit 17-19) :................................................................................................................

urn over[T

heory Section:

T [Total arks]

Time Allowed: 35Minutes

Maximum Marks: 25

NIQUE SCIENCE ACADEMY U

Date

Name

Paper: Physics

1

[Total 6]

Dedicated to My Son Mohammad Irtaza Zain. Code 5054

[2]

are placed at different points in the circuit as shown in Fig. 1.1.

Fig. 1.1

1 A circuit contains two resistors R1 and R2 connected in parallel to a battery. Ammeters A1and A2 and a voltmeter V

R2

R1

A1

A2

2.4 A

12 V

0.8A

V

The following readings are taken from the meters.

reading on the voltmeter V = 12 Vreading on ammeter A1 = 2.4 Areading on ammeter A2 = 0.8 A

(a) Calculate the resistance of resistor R1.

resistance = ............................................ Ω

(b) Calculate the power dissipated in resistor R2.

power = ............................................ W [2]

(c) Calculate the combined resistance of the two resistors R1 and R2 connected in parallel.

resistance = ............................................ Ω [2]Irtaz

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Fig. 2.1

Fig. 2.1 and connects the materials in turn in the gap between P and Q.2 (a) A student tests to see whether certain materials conduct electricity. He uses the circuit in

A

6 V battery

P Q

X

(i) What is the purpose of component X in the circuit?

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(ii) State how the student can tell if a certain material conducts electricity.

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(iii) Which of the following materials is a good conductor of electricity? Put a tick alongside each material that is a good conductor.

copper

glass

iron

nylon

perspex [1]

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Fig. 2.2

The student now connects a small heater in the gap in the circuit, as shown in Fig. 2.2. He (b) wishes to determine the resistance of the heater.

A

6V battery

heater

X

(i) What other meter must he connect in the circuit, in order to determine the resistance?

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(ii) On Fig. 2.2, draw this meter in the correct position in the circuit. [1]

Fig. 2.4 shows an incomplete circuit diagram of the fire.

Fig. 2.3

Fig. 2.3 shows a radiant electric fire with 3 heating elements, each of which operates at full (c) temperature when 250 V is connected across it.

(i)

There are 2 switches. The top switch controls one heating element and the bottom switch controls two heating elements connected in parallel.

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Dedicated to My Son Mohammad Irtaza Zain. Code 5054 [Turn over

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[Total: 11]

resistance = ................................................. [3]

Complete Fig. 2.4, showing all the electrical connections. [2]

Fig. 2.4

250V a.c.

(ii) The current in one heating element is 2.5 A when it is connected to the 250 V supply. Calculate the resistance of the heating element.

(iii) All three heating elements are switched on. Which statement about the total resistance of the electric fire is correct? Tick one box.

no resistance

smaller resistance than in (c)(ii)

same resistance as in (c)(ii)

larger resistance than in (c)(ii) [1]

Fig. 3.1

Fig. 3.1 shows a nylon rod being rubbed with a woollen cloth.3

rod cloth

The rod becomes negatively charged.

(a) (i) Explain how rubbing the nylon rod makes it negatively charged.

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(ii) State what happens to the cloth as the rod becomes negatively charged.

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Dedicated to My Son Mohammad Irtaza Zain. Code 5054

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On Fig. 3.2, draw the distribution of positive and negative charges on the sphere. [2]

Fig. 3.2

Fig. 3.2 shows the negatively-charged rod placed near to a conducting sphere. The sphere is (b) suspended by an insulating thread.

insulating thread

negatively-chargedrod

– –– –– –– –– –– –

conductingsphere

(i)

(ii) Explain why the sphere is attracted to the rod.

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[Total 6]2 MCQ SECTION: [Total Marks]

A conductor carries a current of 2.0A.

How long does it take for 10C of charge to pass one point in the conductor?

A 0.20s B 5.0 s C 12s D 20s

A constant-voltage source is connected to a resistor which has a current I through it.

Two more identical resistors are then added in series with the first.

What is the current now?

A4

IB

3

IC I D 3I

2 A B C D 1 A B C D

MCQ Answer SheetIrtaz

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