Maharaja Sawai Man Singh Vidyalaya

Holiday Assignment

Class XII

CHEMISTRY

1.Investigatory project as discussed in class.

2.To write salt analysis for anions (10) of Dilute H2SO4, Conc H2SO4 and independent group in tabular

form with related chemical equation written on left page.

3.Nomenclature exercise (to write name for given structure and draw structure for given name) from

Chapter of Co ordination complexes.

4.Questions from chapter 1 and 2 as given in Board Papers of Year 2011, 2012,2013,2014,2015.

PHYSICS

Dear students ,

Please note the following instructions:

1. Do not attempt the questions which are repeated. 2. Don’t copy the questions, only paste the print outs. 3. Submit your assignments as the school reopens. 4. Do the questions sincerely and seriously.

Enjoy your Vacations

Derivations taken form board Papers

(Unit 1)

1. What is a dielectric ? Why does the capacitance of a parallel plate capacitor increase on introduction of a

dielectric in between these two plates? Derive an expression for the capacitance of such a capacitor having two

identical plates each of area A and separated by a distance ‘x’. The space between the plates has a medium of

dielectric constant ‘k’.

2. State Gauss theorem in electrostatics. Use it to obtain an expression for the electric field at a point near a

uniformly straight charged line.

3. Derive the expression for the energy stored in a parallel plate capacitor. A parallel plate capacitor with air as

dielectric is charged by a dc source to a potential ‘V’. Without disconnecting the capacitor form the source, air is

replaced by another dielectric medium of dielectric constant 10.State the reason, how does a) EF between the

plates b) the energy stored in the capacitor change.

4. Derive the expression for the electric potential at a point along the axial line of an electric dipole. At a point due

to a point charge, the values of EF and potential are 32N/C and 16J/C respectively. Calculate a) magnitude of the

charge b) the distance of the charge from the point of observation.

5. Sketch the graph to show how charge Q given to a capacitor of capacity ‘C’ varies with the potential difference V.

Also derive the energy stored in between the plates of a capacitor.

6. An infinite line charge produces a field of 9 x 104N/C at a distance of 2cm. Calculate the linear charge density.

7. A 12pF capacitor is connected to a 50V battery. How much electrostatic energy is stored in the capacitor?

Ans: (1.5 x 10-8

J).

8. Find the ratio of linear momentum acquired by an alpha particle and a proton accelerated through the same

potential. Ans (√8:1)

9. Consider a uniform EF, E= 3 x 103i N/C. a) What is the flux of this field through a square of 10cm on a side whose

plane is parallel to the y-z plane? B) What is the flux through the same square if the normal to its plane makes a

60°angle with the x-axis? Ans: A) 30Nm2C

-1 b) 15Nm

2/C

10. With the help of a labeled diagram explain the construction, Principle and working of a Van-de- Graff generator.

(Unit 2) 1. Establish the relation between the drift velocity ‘vd’ of the electrons in a conductor of cross section ‘A’, carrying

current ‘i’ and the concentration of free electrons per unit volume of the conductor being ‘n’.

2. State the principle of a potentiometer. Draw a circuit diagram used to compare the emf’s of two primary cells.

Write the formula used. How can the sensitivity of a potentiometer be increased?

3. Define the term current density of a metallic conductor. Deduce the relation connecting current density(J) and the

conductivity (σ) of the conductor, when an EF E is applied on it.

4. Two cells of emf 1.5V and 2V & internal resistance of 1Ω & 2Ω are connected in parallel to pass a current in the

same direction through an external resistance of 5 Ω. A) Draw the circuit diagram. B) Using the Kirchhoff’ s laws

calculate the current through each branch of the circuit and potential difference across the 5 Ω resistor.

5. Explain the principle of Wheatstone Bridge for determining an unknown resistance. How is it realized in actual

practice in the lab?

6. Define resistivity and state its SI unit. State and explain how the resistivity of a conductor varies with temperature.

7. A wire has a resistance of 16Ω. It is melted and drawn into a wire of half its original length. Calculate the resistance

of new wire. What is the percentage change in its resistance?

8 The resistance of two conductors in series is 40 Ω and their resistance becomes 7.5 Ω, when connected in parallel.

Find the resistance of the individual conductors.

9. The 4 arms of a wheat stone bridge are as under, arm AB a resistance of15 Ω arm BC a resistance of 10 Ω arm CD a

resistance of 25 Ω and arm DA a resistance of 20 Ω. A battery with an emf of 2V and internal resistance of 2.5 Ω is

connected across A and C, galvanometer having a resistance of 20 Ω is connected across B & D. Find the current

flowing in the galvanometer.

10. What is the potential gradient in a potentiometer? How can we decrease the value of it? Why do we prefer a ten

wire potentiometer to a four wire potentiometer?

DPP3 1. Why does the electric field inside a dielectric decrease when it is placed in an external electric field? (1)

2. The Plates of a charged capacitor are connected by a voltmeter. If the plates of the capacitor are moved further apart. What will be the effect on the reading of the voltmeter (1)

3. What is the function of dielectric in a capacitor? (1)

4. What is the work done in moving a 2m C point change from corner A to corner B of a square ABCD when a 10m C charge exist at the centre of the square? 1

5. Show mathematically that the potential at a point on the equatorial line of an electric dipole is Zero? (1)

6. A parallel plate capacitor with air between the plates has a capacitance of 8 pF (1pF = 10-12 F). What will be the capacitance if the distance between the plates is reduced by half and the space between them is filled with a substance of dielectric constant 6? 2

7. Two dielectric slabs of dielectric constant K1 and K2 are filled in between the two plates, each of area A of the parallel plate capacitor as shown in the figure. Find the net capacitance of the capacitor? Area of each plate = A/2 (3)

8. Prove that the energy stored in a parallel plate capacitor is given ½ CV2? 3

9 State Gauss’s Theorem in electrostatics? Using this theorem define an expression for the field intensity due to an infinite plane sheet of change of charge density s c/m2? 3

10 (a) Define dielectric constant in terms of the capacitance of a capacitor? On what factor does the capacitance of a parallel capacitor with dielectric depend?

(b) Find the ratio of the potential differences that must be applied across the (1) parallel (2) Series combination of two identical capacitors so that the energy stored in the two cases becomes the same. 3

11

3

12 Keeping the voltage of the charging source constant. What would be the percentage change in the energy stored in a parallel plate capacitor if the separation between its plates were to be decreased by 10%? 3

13. Derive the expression for the electric field due to line charge distribution using gauss law. 3

each question is of 3 marks except : (Q16 = 2mark) M.M.50 1. Keeping the voltage of the charging source constant, what would be the percentage change in the energy stored

in a parallel plate capacitor if the separation between its plates were to be decreased by 10%?

2 Explain how the average velocity of free electrons in a metal at constant temperature, in an electric field,

remains constant even though the electrons are being constantly accelarated by this electric field?

3 Two students X and Y perform an experiment on potentiometer separately using the circuit diagram shown here.

4 Keeping other things unchanged (i) X increases the value of distance R (ii) Y decreases the value of resistance S in the set up. How would these changes affect the position of null point in each case and why?

5 12 cells, each of emf 1.5V and internal resistance 0.5Ω, are arranged in m rows each containing n cells connected in series, as shown. Calculate the values of n and m for which this combination would send maximum current through an external resistance of 1.5Ω

.

6 For the circuit shown here, calculate the potential difference between points B and D

7 Derive a relation for the electric field due to a dipole at the axial line.

8. With the help of neat and labeled diagram derive an expression for internal resistance using a potentiometer.

9. Obtain an expression for the energy stored in a capacitor.

10. Derive an expression for the electric potential due to a dipole at any arbitrary point ‘P’

11. Two capacitors with capacity C1 and C2 are charged to potential V1 and V2 respectively and then connected in

parallel. Calculate the common potential across the combination, the charge on each capacitor, the electrostatic energy stored in the system and the change in the electrostatic energy from its initial value.

12. With the help of a labeled diagram explain the construction working and the principle of Van-de-graff generator

13. If the length of the wire is increased by 10% then calculate the % change in the resistivity.

14 A battery of emf ‘E’ And internal resistance ‘r’ gives a current of 0.5A with and external resistor of 12 Ω and a current of 0.25A with an external resistance of 25 Ω. Calculate internal resistance and emf of the cell.

15 A wire has a resistance of 16Ω. It is melted and drawn into a wire of half its original length. Calculate the resistance of new wire. What is the percentage change in its resistance?

16. Two point electric charges of unknown magnitude and sign are placed some distance apart. The EF is zero at a point not between the charges but on the line joining them. Write two essential conditions for this to happen.

17. An electric dipole of length 2 cm is placed with its axis making an angle of 60° to a uniform E.F of 105 N/C. If it feels a torque of 8√3 Nm, calculate the (a) magnitude of the charge on the dipole,(B) potential energy of the dipole

Test M.M. 20 (Each question carry 2 mark )

1 Derive the expression of an electric field due to a uniformly charged ring at a point ‘P’ which is at a distance ‘r’ from the axis of the ring. Also mention the condition at which this ring behaves at a point charge.

2 Point charges having values +0.1µC, +0.2µC, -0.3µC and -0.2µC are placed at the corners A,B,C and D respectively of a square of side one metre. Calculate the magnitude of the force on a charge of +1µC placed at the center of the square.

3 Two point charges Q and q are placed at distances x and x/2 respectively from a third charge 4q. All the three charges are on the same straight line. Calculate Q in terms of q such that the net force on q is zero.

4 How does the force between the 2 point charges changes, if the dielectric constant of the medium in which they are kept decreases? Justify.

5 Two point charges of unknown magnitude and sign are placed some distance apart. The electric field intensity is zero at a point not between the charges but on the line joining them. Write 2 essential conditions for this to happen.

6 Explain: a) Why EF lines always emanate perpendicular to the surface? B) Give a situation where the EF lines can be discontinuous.

7 8 charged water droplets, each with radius of 1mm and a charge of 10-10C, collapse to form a single drop.Calculate the EF of the bigger drop.

8 Derive an expression for the electrostatic Potential energy of a system carrying ‘n point charges.

9 Three point charges ‘q’, 2q and 8q are to be placed on 9cm long straight line. Find the position where the charges should be placed the potential energy of the system is minimum. In this situation what will be the electric field a the position of charge ‘q’ due to other 2 charges.

10 Derive an expression for the electric field due to a dipole on the axial line.

Test 2 1. Define potential energy. What is the relation between potential and potential energy? Derive the formula for the potential

energy for the two particle system.

2 Derive an expression for the potential energy stored due to 4 set of charges.

3 ABCD is a square of side 5m. Charges of +50C -50C and +50C are placed at A,C and D respectively. Find the net E at B.

4 Define capacitance of a capacitor. Derive an expression for the capacitance of a parallel plate capacitor. Mention its physical significance. Also derive the energy stored in it.

5 “ In a certain region of space, electric field is along Z- direction through out. The magnitude of the electric field is however not constant but increases uniformly along the positive Z- direction at the rate of 105N/Cm. What are the force and torque experienced by a system having a total dipole moment equal to 10-7Cm in the negative direction?

6 Deduce the expression of capacitance between the parallel plate capacitor on inserting a dielectric slab of thickness ‘t’ in between the plates.

7 With the help of a labeled diagram explain the construction ,working and principle of Van-De Graff generator.

8 An infinite plane sheet of charge density 10-8Cm-2 is held in air. How far apart the 2 equi potential surfaces whose potentials differ by 5V?

9 Derive an expression for the electric potential due to a dipole at any arbitrary point ‘P’.

10. Charges each of 2µC is placed at x = 1m, x = 2m ,x = 4m ----- and so on. What is the potential at the origin of the x-axis?

Test 4

1. A pendulum of mass 80mg and carrying a charge of 20nC is at rest in a horizontal uniform EF of 2 x 104N/C. Find the tension in the thread of the pendulum and the angle it makes with the vertical.

2. A particle of mass ‘m’ & carrying charge ‘-q1’ is moving around a charge ‘+q2’ along a circular path of radius ‘r’.

Prove that the period of revolution of the charge –q1 about –q2 is given by qq

rmT

21

3

0

316 επ=

3 Eight charged water droplets each with a radius of 1mm and a charge of 10-10C collapse to form a single drop. Calculate the EF of the bigger drop.

4 If the electric field is given by 6i + 3j + 4k, calculate the electric flux through a surface of area 20 units lying in YZ plane.

5 What is the principle of a potentiometer? Explain with the help of a circuit diagram, the use of potentiometer for

the determination of the internal resistance of a primary cell. Derive the necessary mathematical expression also.

6 A cylindrical wire is stretched to increase its length by 10%. Calculate the percentage increase in resistance.

7 Define resistivity of a conductor. Explain the variation of resistance with temperature in a) metallic conductors b) semiconductors.

8 Establish a relation between drift velocity ‘vd’ of an electron in a conductor of cross section ‘A’ , carrying current ‘i’ and concentration ‘n’ of free electrons per unit volume of conductor. Hence obtain the relation between current density and drift velocity.

9 The four arms of a wheat stone bridge are as under, arm AB a resistance of 5 Ω arm BC a resistance of 10 Ω arm CD a resistance of 15 Ω and arm DA a resistance of 20 Ω. A battery with an emf of 2V and internal resistance of 0.5V is connected across A and C, galvanometer having a resistance of 20 Ω is connected across B and D. Find the current flowing in the galvanometer.

10. The resistance of two conductors in series is 40 Ω and their resistance becomes 7.5 Ω, when connected in parallel. Find the resistance of the individual conductors.

Time 3 hrs Test 1 based on (Electrostatics and Current Electricity ) 2012-13 M.M 70

1. What is the dielectric constant for a metal conductor?

2 State Kirchhoff’s laws .

3 Write two special characteristics of magnanin due to which it is used in making standard resistances.

4 Why do we prefer a ten wire potentiometer to a four wire potentiometer

5 State Gauss theorem.

6 Sometimes a balance point may not be obtained on the potentiometer wire. Why?

7 Identify the Physical quantity having SI unit as V/m.

8 Define relaxation time and relative permitivity.

9 Obtain an expression for the loss of energy on sharing charges in the case of a capacitor.

10 The electric potential ‘V’ at any point x, y, z in space is given V = 4x2 volt. Calculate the EF at the point (1m, 0, 2m).

11 A wire has a resistance of 16Ω. It is melted and drawn into a wire of half its original length. Calculate the resistance of new wire. What is the percentage change in its resistance?

12 Explain the colour code and tolerance of resistance along with an example.

13 Define dipole moment and express it mathematically. Also write its SI unit

14 Obtain an expression for the EF due to a spherical charge distribution of radius ‘R’ at r>R , r<R and r=R

15 The electric field and electric potential at any point due to a point charge kept in air is 20 N/C and 10 JC-1 respectively. Compute the magnitude of this charge.

16 Two point electric charges of unknown magnitude and sign are placed some distance apart. The EF is zero at a point not between the charges but on the line joining them. Write two essential conditions for this to happen.

17 A ) Sketch a graph to show how the charge Q acquired by a capacitor of capacitance C varies with increase in potential difference between its plates.

B) Sketch a graph to show how the capacitance C of a capacitor varies with the charge Q given to it.

18 An electric dipole of length 2 cm is placed with its axis making an angle of 60° to a uniform E.F of 105 N/C. If it feels a torque of 8√3 Nm, calculate the (a) magnitude of the charge on the dipole,(B) potential energy of the dipole

19 27 drops of water of the same size are equally and similarly charged. They are then united to form a bigger drop. How will capacitance and potential change?

20 Three point charges ‘q’, 2q and 8q are to be placed on 9cm long straight line. Find the position where the charges should be placed the potential energy of the system is minimum. In this situation what will be the electric field a the position of charge ‘q’ due to other two charges.

21 Obtain an expression to calculate the internal resistance of a cell using potentiometer.

22 With the help of neat and labeled diagram explain the principle ,construction of a metre bridge. Also obtain the necessary expression to calculate the unknown resistance.

23 Discuss the effect of temperature on resistivity in the case of metals and semiconductors.

24 In a metre bridge, the balance point is found to be at 39.5 cm from the end A, when the resistor Y is of 12.5 ohm. Determine the resistance of X. Why are the connections between resistors in a metre bridge made of thick copper strips? What happens if the galvanometer and cell are interchanged at the balance point of the bridge? Would the galvanometer show any current?

25 Obtain an expression for the electric field due to linear charge distribution using gauss theorem.

26 If the length of the wire is increased by 10% then calculate the % change in the resistivity.

27 A battery of emf ‘E’ And internal resistance ‘r’ gives a current of 0.5A with and external resistor of 12 Ω and a current of 0.25A with an external resistance of 25 Ω. Calculate internal resistance and emf of the cell.

28 How the capacitance of a parallel plate capacitor gets affected when a) conducting plate of thickness ‘t’ is inserted b) when a dielectric slab is inserted.

29 Give the principle of a Van-de- Graff generator. With the help of a labeled diagram describe its construction and the working. How is the leakage of charge minimized from the generator.

30 The four arms of a wheat stone bridge are as under, arm AB a resistance of 5 Ω arm BC a resistance of 10 Ω arm CD a resistance of 15 Ω and arm DA a resistance of 20 Ω. A battery with an emf of 2V and internal resistance of 0.5V is connected across A and C, galvanometer having a resistance of 20 Ω is connected across B and D. Find the current flowing in the galvanometer.

Test 1 Show that the normal component of electrostatic field has a discontinuity from one side of a charge surface to another given

by: ( )0

12 ˆεσ=− nEE

rr

2 One million drops each of radius 2cm and having a charge of 4 x 10-9C collapse to form a bigger drop. Find the potential of the bigger drop.

3 27 spherical drops each of radius 3mm carrying a charge of 10-12C of charge are combined to form a bigger drop. Find the capacitance and potential of the bigger drop.

4 Four charges each of +3µC, +5 µC,+3 µC,+5 µC are placed at the four corners of a square having a +4 charge at the centre. Find the total charge at +5 µC.

5 Derive an expression for the electric potential due to a dipole at any arbitrary point ‘P’.

6 Derive an expression for the parallel plate capacitor when a dielectric slab is inserted in between it.

7 With the help of a labeled diagram explain the principle, construction &working of a Van-de graff generator.

8 Define energy density. Also obtain the necessary express on for the electric field due to line charge distribution using Gauss law.

9 Derive an expression for the electric field due to a dipole at equatorial point.

10 Give reasons for the following:

a) Why can’t be the electric lines of force be discontinuous? b) Why electric field lines cannot intersect each other? c) Why electric field lines always emit perpendicular to the surface? d) Why glass rod always becomes positively charged on rubbing with silk cloth? e) Why electric potential is zero at the mid point of a dipole? f) At what position a dipole in an electric field has maximum stability g) What is the SI unit of the surface integral of electric field? h) Draw a graph of electric field due to a spherical charge w.r.t. distance . i) Draw a graph of electric potential due to a spherical charge w.r.t. distance j) An isolated metallic conductor is positively charged. Will its mass increase, decrease or remain the same?

Practice sheet DPP2 1 Show does the force between two point charges change if the dielectric constant of the medium in which they are kept increase?

2 A charged rod P attracts rod R where as P repels another charged rod Q. What type of force is developed between Q and R? 3 A free proton and a free electron are placed in a uniform field. Which of the two experience greater force and greater acceleration? 4 No two electric lines of force can intersect each other? Why? 5 A particle of mass m and charge q is released form rest in a uniform electric field of intensity E. calculate the kinetic energy it

attains after moving a distance s between the plates? 6 Two point charges +q and +9q are separated by a distance of 10 a. Find the point on the line joining the two changes where electric

field is zero? 7 Define the term dipole moment P of an electric dipole indicating its direction. Write its S.I unit. An electric dipole is placed in a

uniform electric field E . Deduce the expression for the Torque acting on it. 8 Two charges each 2 x 10-7 C but opposite in sign forms a system. These charges are located at points A (0,0, -10) cm

and B(0,0, +10) cm respectively. What is the total charge and electric dipole moment of the system? 9 (a) Sketch electric lines of force due to (i) isolated positive change (ie q>0) and (ii ) isolated negative change ( ie q<0) 10 Two point changes q and –q are placed at a distance 2a apart. Calculate the electric field at a point P situated at a distance r

along the perpendicular bisector of the line joining the charges. What is the field when r >> a?

11 Which physical quantity has its S.I unit (1) Cm (2) N/C 12 An electric dipole when held at 30ᴼ with respect to a uniform electric field of 104 N/C experienced a Torque of 9 x 10-26 Nm.

Calculate dipole moment of the dipole? 13 A sphere of radius r1 encloses a change Q. If there is another concentric sphere S2 of radius r2 (r2 >r1) and there is no

additional change between S1 and S2. Find the ratio of electric flux through S1 and S2? 14 Electric charge is uniformly distributed on the surface of a spherical balloon. Show how electric intensity and electric potential

vary (a) on the surface (b) inside and (c) outside. 15 Two point electric charges of value q and 2q are kept at a distance d apart from each other in air. A third charge is to be kept

along the same line in such a way that the net force acting on q and 2q is zero. Calculate the position of charge in terms of q and d.

16 (a) What is an equi-potential surface? Show that the electric field is always directed perpendicular to an equi-potential surface. (b) Derive an expression for the potential at a point along the axial line of a short electric dipole?

17. Draw a graph showing the capacitance with respect to distance.

Test 1 M.M 25 15/04/14 1. Can a body hold a charge of 0.8x10-19C? Justify.1

2. Why electric field lines emanate perpendicular to the surface of the conductor ? (1)

3. Identify the physical quantity Vm. Is it a scalar? 1

4. Obtain an expression for the electric potential due to a dipole at any arbitrary point P. (2)

5. State and prove the important properties of equi- potential surfaces(2)

6. An infinite plane sheet of charge density 10-8Cm-2 is held in air. In this situation how far apart are two equipotential surfaces, whose potential difference is 5V? (2)

7. Two charges 3 x 10-8C and -2x10-8C are located 15cm apart. At what point on the line joining the two charges is the electric potential zero? (2)

8. To what potential we must charge an isolated sphere of radius 14cm so that the surface charge density is equal to 1 µCm-2? (2)

9. 27 spherical drops of radius 3mm carrying 10-12C of charge are combined to form a single drop. Find the potential of a bigger drop?(2)

10. Draw separate graphs to show the variation of a) Electric field b) Potential Vs distance from the centre to a far point P from centre. 2

11. Derive an expression for the electric field for a uniform line charge distribution. (2).

12. Mention 4 properties of electric lines of force.(2)

13. 3 charges of +5µC, +10µC and -10µC are placed in air at the corners of A,B and C of an equilateral triangle having each side equal to 5cm. Find the resultant force on charge A. (2)

14 An infinite number of charges each equal to 4µC are placed along x-axis at x=1m, x=2m, x=4m, x=8m and so on. Find the total charge on 1C placed at the origin. (2)

26 2 fixed point charges 4Q and 2Q are separated by a distance x. Where should a third charge q be placed for it to be in equilibrium?

a) 0.586m from charge 4Q b) 0.586m from charge 2Q c) 5.586m from charge 4Q d) 5.586m from charge 2Q

27 Two small spheres each of mass 10-6Kg are suspended from a point by silk threads 50cm long. These are equally charged and repel each other to a distance of 20cm apart. Calculate the charge on each sphere.

a) 3.01 x 10-9C b) 3.01 x 10-3C c) 3.01 x 10-5C d) 3.01 x 10-12C

28 Charges –q,-q +2q are placed at the corners of an equilateral triangle of side ‘l’ then magnitude of resultant electric dipole moment will be :

a) Ql b)2ql c) √3ql d) 4ql

29 E is the intensity of EF at a distance ‘r’ from the entre of the metallic charged sphere of radius ‘R’. Then work done in taking charge q0 from infinity to that point will be:

a) q0 RE b) q0 RE/2 c) q0 rE d) q0 rE/2

30 A ring of radius R has a charge +q. A charge q0 is freed from the distance √3R on its axis, when it reaches to the centre of the ring its K.E. becomes: a) k qq0/R b) k qq0/2R c) k qq0/√3R d) k qq0/3R

31 Two point free charges +4q and +9q are placed at a distance ‘r’ apart. What is the value of the third charge so that when it is placed between the two charges the system remains in equilibrium:

a) –(13/5) q b)-(36/25)q c) (16/25) q d) -(2/3)q

32 The EF as we go into the sphere of uniformly charged sphere ,will be: a) same at al points b) same as on the surface c) increases d) decreases

33 Two small spheres, each having a mass of 10g and charge 0.1 µC, are at rest in limiting equilibrium on a rough horizontal surface with a separation of 5cm between their centres. The coefficient of friction between each sphere and the surface is the same. The value of this coefficient is :

a) 0.4 b) 0.46 c) 0.56 d) 0.36

34 Two charges q and 4q are placed at a certain distance apart. A third charge Q is placed at the middle point of the line joining them. The magnitude and the nature of Q is such that the net force on q is zero will be :a) Q= -2q b) Q = -q c) Q = -q/2 d) Q = -5q/2

35 A small metal ball of mass m is suspended from a thread of length l between the plates of a large plane capacitor. How will the period of oscillations of such a pendulum change, if a charge +q is placed on the ball and the upper plate is a) positively charged b) negatively charged. a) increases b) decreases c) remains same d) none.

Objective Sheet (Electrostatics) PS 3

1 2 charged particles of masses ‘m’ and 2m have charges +2q and +q respectively. They are kept in a uniform electric field far away from each other and then allowed to move for the same time. Find the ratio of their K.E a) 6:1 b) 8:1 c) 5:3 d) 1:1

2 A thin fixed ring of radius 1m has a positive charge 1 x 10-5C uniformly distributed over it. A particle of mass 0.9g and having a negative charge of 1 x 10-6C is placed on the axis at a distance of 1cm from the centre of the ring. The motion of the negatively charged particle is nearly SHM. Calculate the time period of oscillations. a) π/4 b) π/6 c) π/5 d) π/7

3 An electron moves from rest from a point at which a potential is 50V to another point at which potential is 70V. Its kinetic energy in the final state will be: a) 3.2 x 10-20J b) 3.2 x 10-19J c) 3.2 x 10-21J d) 3.2 x 10-18J

4 The electric charge on drop B is 1.6 x10-19C an its mass is 1.6x 10-14Kg. If the drop is in equilibrium then the potential difference between the plates will be: a) 5 x 105V b) 5 x 104V c) 104V d) 15 x 105V

10mm .

5 The bob of a pendulum of mass 8µg carries an electric charge of 39.2x10-10C in an electric field of 20 x 103V/m an it is rest. The angle made by the pendulum with the vertical will be : a)27о b) 45о c) 87о d)127о

6 An electron moves through a distance of 4cm in a uniform EF 5 x 104 N/C. The time taken by the e-1: a) 2.9 x10-7s b) 2.9 x10-

8s c) 2.9 x10-9s d) none

7 The coulomb force between two charges q1 & q2 distance d apart, is F. If F is constant if the magnitude of q2 is halved &distance between them is changed to x then the value of x:d will be : a) 1/√2 b) √2 c) ½ d) 2

8 Electric charge of 10-5C is uniformly distributed on a thin ring of radius 1m. A particle of mass 0.9gm and carrying charge of 1µC is lying on the axis of the ring at a distance of 1cm from centre. The angular frequency of the particle will be: a) 100 rad/sec b) 10rad/sec c) 5rad/sec d) zero.

9 Four charges each of 2 µC are lying at x = 0,2,4,8cm. The net force on the charge situated at x = 2cm will be: a) 5N b) 2.5N c) 10N d) zero

10 An alpha particle of energy 10MeV is moving towards a stationary gold nucleus (Z= 79) . The minimum distance of alpha particle from the nucleus will be: a) 2.28 x 10-14m b) 5.56 x 10-14m c) zero d)0.28 x 10-14m

11 An electric dipole, when held at an angle of 30 with respect to a uniform EF of 104N/C experiences a torque of 9 x 10-26Nm. Calculate the dipole moment. a) 2.8 x 10-29Cm b) 1.8 x 10-29Cm c) 2.8 x 10-19Cm d) none.

12 A small metal ball of mass m is suspended from a thread of length l between the plates of a large plane capacitor. How will the period of oscillations of such a pendulum change: + + -

+ -

A B A + - B

+ -

+ -

+ -

a) increases b) decreases c) remains same d) none

13 2 point charges of +20 µC and +80 µC are placed 18m apart. Find the position of the point where the E.F. is zero

a) 6cm away from +20 µC b) 12cm away from +80 µC c) both a and b d) 14cm away from +20 µC

14 An inclined plane making an angle of 30 with the horizontal is placed in a uniform horizontal electric field E of 100V/m as shown in the figure. A particle of mass 1Kg and charge 0.01 µC is allowed to slide down from rest from a height of 1m. If the coefficient of friction is 0.2, find the time it will take the particle to rach the bottom. a) 1.345s b) 2.456s c) 3.453s d)0.785s

E = 100V/m

15 Two point charges are 3m apart and their combined charge is 20µC. If the force between them is 0.075N, the magnitude of the charges will be:

a) 15 µC & 5 µC b) 16 µC & 4 µC c) 18 µC & 6 µC d) None.

16 A charge Q is divided on two small objects separated by a certain distance. The values of the charges on the objects so that the force between them is maximum will be : a) q = Q/2 b) q = 2Q c) q= Q /4 d) q= 4Q

17

Two particles having charges q1= +4q and q2 =-q are fixed at a separation of ‘r’. At what point should a proton be placed so that it is in equilibrium.

a) x = r b) x = 2r c) x= r/2 d) x = 4r.

18 A pendulum bob of mass 80mg and carrying a charge of 2 x 10-8C is at rest in a uniform horizontal electric field of 20,000V/m. The tension in the thread and the angle it makes with the vertical will be:

a) 70mN & 30о b) 80mN & 27.2 о c) 75mN & 32.5 о d) 60mN & 43.8 о

19 Two equally charged identical metal spheres A and B repel each other with a force 2 x 10-5N. Another identical charged sphere C is touched to A and then placed at the mid point between A and B. What is the net force on C?

a) 5 x 10-5N b) 6 x 105N c) 8.5 x 10-5N d) 2 x 10-5N

20 Two identical charged spheres are suspended by strings of equal lengths. The string makes an angle 30ο with each other. When suspended in a liquid of density 800Kg/m3,the angle remains the same. What is the dielectric constant of the liquid? The density of the material of the sphere is 1600Kg/m3. a) 1.5 b) 3.4 c) 2 d) 4

21 A pith ball A of mass 9 x 10-5Kg carries a charge of 5 µC. What must be the magnitude and sign of the charge on the pith ball B held 2cm directly above the pith ball A, such that the pith ball A, remains stationary?

a) 7.84 x 10-12µC b) -7.84 x 10-12 µC c) 7.84 x 1012 µC d) -7.84 x 1012 µC

22 Four point charges qa = 2 µC, qb = -5 µC, qc = 2 µC and qd = -5 µC are located at the corners of a square ABCD of side 10cm. What is the force on charge of 1 µC placed ot the centre of the square?

a) 2 µC b) zero c) 3/2 µC d) 5/2 µC.

23 How far apart should the 2 electrons be, if the force each exerts on the other is equal to the wt. of the elec.?a) 5.08m b) 8.05m c) 7m d) 6.55m

24 Charges of +5 µC, +10 µC and -10 µC are placed in air at the corners A,B and C of an equilateral triangle ABC, having each side equal to 5cm. Determine the resultant force on the charge at A.

Test 2 M.M. 70 1 Force of attraction between two point electric charges placed at a distance d in a medium is F. What distance apart should

these be kept in the same medium, so that force between them becomes F/3?1

2 The distance of the field point on the equatorial plane of a small electric dipole is halved. By what factor will the electric filed due to the dipole change? [1]

3 Draw one equipotential surface (1) In a uniform electric field (2) For a point change (θ < o)? [1]

4 If the amount of electric flux entering and leaving a closed surface are φ1& φ2 respectively. What is the electric charge inside the surface? (1 )

5. Derive an expression for the total work done in rotating an electric dipole through an angle θ in a uniform electric field?[2]

6. If C1 = 3pF and C2 = 2pF, calculate the equivalent capacitance of the given network between points A & B? [2]

7. Prove that energy stored per unit volume in a capacitor is given by 1/2 ∈o E2 , where E is the electric field of the capacitor? [2]

8. (a) An air capacitor is given a charge of 2µ C raising its potential to 200 V. If on inserting a dielectric medium, its potential falls to 50 V, what is the dielectric constant of the medium?

(b) A conducting stab of thickness ‘t’ is introduced without touching between the plates of a parallel plate capacitor separated by a distance d (t<d). Derive an expression for the capacitance of a capacitor? (3)

9. Two point charges +q and +9q are separated by a distance of 10 a. Find the point on the line joining the two changes where electric field is zero? (3)

10. With the help of a labeled diagram explain the principle, construction and working of a Van-de-graff generator. (3)

11. Why EF lines always emanate perpendicular from the surface of a conductor? (1)

12. Two charges each 2 x 10-7 C but opposite in sign forms a system. These charges are located at points A (0,0, -10) cm & B(0,0, +10) cm respectively. What is the total charge and electric dipole moment of the system? (3)

13. The graph shows the variation of voltage V across the plates of two capacitors A and B versus increase of charge Q stored on

a) 100N parallel to BC b) 140N Perp to BC c) 180N Perp to BC d) 180N Parallel to BC

25 Four charges +q, +q, -q and –q are placed respectively at the four corners A, B ,C and D of a square of side ‘a’. Calculate the force on a charge Q placed at the centre of the square.

a) Q = -2 (21/2) q b) Q = - (21/2) q c) Q = -2 (2-1/2) q d) none

them. Which of the two capacitors have higher capacitance? Give reason ? (2)

14. State Gauss’s Theorem in electrostatics? Using this theorem define an expression for the field intensity due to an infinite plane sheet of

change of charge density σ c/m2? 3

Test 2 M.M. 70 1 Force of attraction between two point electric charges placed at a distance d in a medium is F. What distance apart should

these be kept in the same medium, so that force between them becomes F/3?1

2 The distance of the field point on the equatorial plane of a small electric dipole is halved. By what factor will the electric filed due to the dipole change? [1]

3 Draw one equipotential surface (1) In a uniform electric field (2) For a point change (θ < o)? [1]

4 If the amount of electric flux entering and leaving a closed surface are φ1& φ2 respectively. What is the electric charge inside the surface? (1 )

5. Derive an expression for the total work done in rotating an electric dipole through an angle θ in a uniform electric field?[2]

6. If C1 = 3pF and C2 = 2pF, calculate the equivalent capacitance of the given network between points A & B? [2]

7. Prove that energy stored per unit volume in a capacitor is given by 1/2 ∈o E2 , where E is the electric field of the capacitor? [2]

8. (a) An air capacitor is given a charge of 2µ C raising its potential to 200 V. If on inserting a dielectric medium, its potential falls to 50 V, what is the dielectric constant of the medium?

(b) A conducting stab of thickness ‘t’ is introduced without touching between the plates of a parallel plate capacitor separated by a distance d (t<d). Derive an expression for the capacitance of a capacitor? (3)

9. Two point charges +q and +9q are separated by a distance of 10 a. Find the point on the line joining the two changes where electric field is zero? (3)

10. With the help of a labeled diagram explain the principle, construction and working of a Van-de-graff generator. (3)

11. Why EF lines always emanate perpendicular from the surface of a conductor?(1)

12. Two charges each 2 x 10-7 C but opposite in sign forms a system. These charges are located at points A (0,0, -10) cm & B(0,0, +10) cm respectively. What is the total charge & electric dipole moment of the system?(3)

13. The graph shows the variation of voltage V across the plates of two capacitors A and B versus increase of charge Q stored on them. Which of the two capacitors have higher capacitance? Give reason ?(2)

14. State Gauss’s Theorem in electrostatics? Using this theorem define an expression for the field intensity due to an infinite plane sheet of change of charge density σ c/m2?(3)

15. Two point electric charges of value q and 2q are kept at a distance d apart from each other in air. A third charge θ is to be kept

along the same line in such a way that the net force acting on q and 2q is zero. Calculate the position of charge θ in terms of q and d. (3)

16 Derive an expression for the potential at a point along the axial line of a short electric dipole? (3)

17. An electric dipole when held at 300 with respect to a uniform electric field of 104

N/C experienced a Torque of 9 x 10-26

Nm. Calculate dipole moment of the dipole? (2)

18. A 500µC charge is at the centre of a square of side 10cm. Find the work done in moving a charge of 10 µC between two diagonally opposite points on the square. (3)

19. Two fixed point charges +4e and +e are separated by a distance ‘a’. Where should be a third point charge be placed for it to be in equilibrium? (3)

20. The galvanometer, in each of the two given circuits, does not show any deflection. Find the ratio of the resistors R1

and R2, used in these two circuits. (5)

21. With the help of a labeled diagram explain the principle, construction and the method to calculate the internal resistance of a potentiometer .(3)

22. Derive a relation for current and drift velocity in a conductor.(3)

23. On what principle does a metre bridge work? Draw a circuit diagram and explain how the device can be used to determine the unknown resistance?(3)

24. Two wires of equal length, one of copper and the other of manganin have the same resistance. Which wire is thicker? (2)

25. Define the following: A) mobility b) current density c) drift velocity (3)

26. Derive the expression to show the variation in resistivity with respect to temperature in metals and semiconductors. (3)

27. Derive an expression to obtain maximum current in the mixed combination of cells. (3)

28. A cylindrical wire is stretched to increase its length by 5%. Calculate the percentage change in its resistance. (3)

Practice Sheet 1. Name the scientist who first demonstrated that two kinds of charges exit.

2. Name the scientist who introduced the words, “positive” in place of vitreous and “negative in place of resinous.

3. Which is larger – charge on an electron or one coulomb.

4. Give a practical example to show that the electrostatic force is much stronger than the gravitational force.

5. Consider two charged particles A and B separated by a distance ‘r’. Now if another charged particle C is brought near them, how is the electrostatic force between A and B will be affected?

6. A pair of charges repel each other with a force of 810N in vacuum. If the pair is placed at same distance apart in water, with what force they repel each other?

7. Can two like charged bodies attract each other? If yes, how?

8. X and Y have the same mass and identical sizes. They are rubbed and hence X becomes X++ and Y becomes Y- -. Will X ++ and Y- -have same mass?

9. Why do gramophone records get covered with dust easily?

10. A charged rod attracts small pieces of dry cork dust which after touching the rod, often jumps violently away from it. Give reason.

11. A positively charged glass rod attracts a suspended object. Is it necessary that the object is negatively charged?

12. A positively charged glass rod repels a suspended object. Is it necessary that the object is positively charged?

13. Why are rubber used in making aircrafts tyres a little conducting?

14. Is there any way of producing high voltage in your body without getting a shock?

15. Write unit and dimensional formula of electric field.

16. Why a test charge should be extremely small when measuring the electric field at a point.

17. Give two examples of linear charge distribution.

18. Name the scientist who introduced the concept of lines of force.

19. Do the electric lines of force actually exist?

20. A charge +Q is placed at a small distance from an infinite metal plate. Draw the electric lines of force.

21. An ebonite rod is rubbed with wool or fur. What type of charges do they acquire.

22. A charged particle is free to move in an electric field. Will it always move along the electric field.

23. In a medium the force of attraction between two point electric charges, distance ‘d’ apart is F. What distance apart should these be placed in the same medium so that the between them becomes 3F?

Practice Sheet 1. Name the scientist who first demonstrated that two kinds of charges exit.

2. Name the scientist who introduced the words, “positive” in place of vitreous and “negative in place of resinous.

3. Which is larger – charge on an electron or one coulomb.

4. Give a practical example to show that the electrostatic force is much stronger than the gravitational force.

5. Consider two charged particles A and B separated by a distance ‘r’. Now if another charged particle C is brought near them, how is the electrostatic force between A and B will be affected?

6. A pair of charges repel each other with a force of 810N in vacuum. If the pair is placed at same distance apart in water, with what force they repel each other?

7. Can two like charged bodies attract each other? If yes, how?

8. X and Y have the same mass and identical sizes. They are rubbed and hence X becomes X++ and Y becomes Y- -. Will

X++ and Y- -have same mass?

9. Why do gramophone records get covered with dust easily?

10. A charged rod attracts small pieces of dry cork dust which after touching the rod, often jumps violently away from it. Give reason.

11. A positively charged glass rod attracts a suspended object. Is it necessary that the object is negatively charged?

12. A positively charged glass rod repels a suspended object. Is it necessary that the object is positively charged?

13. Why are rubber used in making aircrafts tyres a little conducting?

14. Is there any way of producing high voltage in your body without getting a shock?

15. Write unit and dimensional formula of electric field.

16. Why a test charge should be extremely small when measuring the electric field at a point.

17. Give two examples of linear charge distribution.

18. Name the scientist who introduced the concept of lines of force.

19. Do the electric lines of force actually exist?

20. A charge +Q is placed at a small distance from an infinite metal plate. Draw the electric lines of force.

21. An ebonite rod is rubbed with wool or fur. What type of charges do they acquire.

22. A charged particle is free to move in an electric field. Will it always move along the electric field.

23. In a medium the force of attraction between two point electric charges, distance ‘d’ apart is F. What distance apart should these be placed in the same medium so that the between them becomes 3F?

PART 2 1. State law of conservation of charge. Give two examples showing conservation of charge.

2. Differentiate between electric charge and mass by mentioning few points of differences.

3. Why electrostatic experiments do not work properly on humid days?

4. A comb rubbed through dry hair attracts small bits of paper. Why? What happens if the hair is wet or if it is a rainy day?

5. Is it observed that if a metal rod is rubbed while holding it in hand, it does not get charged. Why?

6. Two positive charges ‘q’ and 4q are placed at 6cm. locate the neutral point and draw lines of force.

7. Write 6 properties of the electric lines of force.

8. Obtain an expression for the electric field E at a point on the axis of a ring over which charge is distributed uniformly. Hence show that for a point at large distance from the ring., it behaves like a point charge.

9. A pith ball A having mass 9 x10-5Kg carries a charge of 5µC. It is intended to keep this ball stationary by preventing fall due to gravitational force by placing another charged pith ball B 2cm directly above it. What should be the magnitude and sign of charge on B?

10. The separation between the proton and the electron in the hydrogen atom is about 5.3 x 10-11m. What are the magnitudes of a) the electrostatic force and b) the gravitational force between these two particles?

11. Two small spheres each of mass 10mg are suspended from by threads 0.5m long. They are equally charged and repel each other to a distance of 0.28m. If g=10m/s2, what is the charge on each?

12. Charges of +5 µC, +10 µC and -10 µC are placed in air at the corners of A, B and C of an equilateral ΔABC, having each side equal to 5cm. Determine the resultant forces on charge at A.

13. Two charges each of +Q units are placed along a line. A third point charge is placed between them. At what position and for what value of third charge will the system be in equilibrium?

14. Two charges of +10 µC and -40 µC respectively are placed 12cm apart. Find the position of the point, where electric field is zero.

15. A dipole of length 0.1m consists of two charges 200 µC. What is its electric dipole moment? Calculate the electric field due to the dipole at a point on the axial distance 0.2m from one of the charges in air.

16. If an oil drop of weight 3.2x10-13N is balanced in an EF of 5x 105 V/m. Find the charge on the oil drop.

17. Two identical balls each of mass ‘m’ and charge ‘q’ are suspended with threads of length ‘l’. If θ is the angle which each thread

makes with vertical in equilibrium prove that the separation (x) is given by 3

1

0

2

2

=

mg

lqx

πε

18. Two point electric charges of values q and 2q are kept at a distance ‘d’ apart from each other in air. A third charge Q is to be kept along the same line in such a way that the net force acting on q and 2q is zero. Calculate the position of charge Q in terms of q and d.

ACCOUNTANCY

1. Comprehensive Project as per discussion in the class and CBSE Guidelines. 2. Additional questions of Chapter 2 and 3 (Book Accountancy Part I by S.C. Sharma)

ECONOMICS

1. Learn & make notes of Budget (Unit- 8 )

2. Additional questions of chapter 4 Demand and elasticity of demand

(Page No.4.19,4.20,4.21,4.22 & 4.26(HOTS and CBSE )

BUSINESS STUDIES

Q 1 .D ltd. Wants to modify its exiting product ,CD players in market due to decreasing sales.

What decisions should each level of management take to give effect to this decision.

Q 2. Explain the Nature of Co ordination..

Q3. Principles of Taylor and Fayol are mutually complementary . Do you agree. Give three

points of differences between their contributions.

Q 4. Explain various characteristics of Principles of Management.

Q 5. Why is understanding of business environment important for managers? Explain

Q 6. State any five impacts of government policy changes on business on business and industry.

Q 7. Sangram Ltd imports various computer parts from china and assembles them to make

a complete Computer . The total work involve three different task : assembling , labeling

and packaging of Computers . Each employee of the company independently performs all the

three task, as a result. No employee is able to gain specialization in a particular field and the Co.

is unable to fulfill the orders on time.

1. State and identify the principle, which can be followed by Sangrame Ltd. To overcome this problem ?

2. Will the use of this principle enables the employees to gain specialization.

3 . Can the Co. implement this principle in managerial work.

Q8. Lately, many Companies have planned for significant investment in organized retailing

In India several factors have prompted their decisions in this regard. Customer income

Is rising, people have developed a taste for better quality products even though they have to

more. The aspiration levels have increased. The Govt. has also liberalized its economic policies.

In this regard and permitted even cent percent foreign direct investment in some sectors of

retailing.

1. Identify changes in business environment under different heads : economic , social , technological

Political and legal , that

Q9. Prepare ONE PROJECT on the any of one of the chapter s

1. Principles of Management 2. Elements of Business Environment

3. Marketing Management

As per CBSE guidelines and discussion in the class.

Psychology

Chapter 1

Read Chapter 1 and Chapter 2 and attempt questions at the end of the chapters.

Complete Practicals Report File –SPM, HSPQ.

ENGLISH

To be done in English notebook

1. You are Harish Sahai. Recently you came across an advertisement for the post of Sales Executive in Daikin Aircon Ltd, Alwar. Write an application for this job in about 125-150 words, giving your complete bio-data separately.

2. Some people believe that ragging is a menace and must be banned from campuses. Others believe it is a good way of making fresh entrants feel at home in school or college. What is your view? Discuss it in an article for your school magazine in about 150 -200 words. Support your view with relevant examples. You are Manoj/Mitali Sharma

ENTREPRENEURSHIP

UNIT 3 : Enterprise Marketing – Complete the assignments given on page 139 in the text book (Part D, E, F, G and H).

Project- Prepare the business plan as per the CBSE outline given on page 269 in the text book.

HISTORY

Start Researching and collecting matter for the project work as per the CBSE guidelines mailed

to you

Computer Science

Explore the following topics and present a handwritten report.

WWW, Hyper Text Markup Language(HTML), eXtensible Markup Language(XML),Hyper Text Transfer

Protocol(HTTP),Domain Name, URL, Website, Web Servers, Web Hosting, Web Scripting-client side(VB

Script, Java Script, PHP) and Server side(ASP, JSP, PHP),Web 2.0(for social networking) , Cookies, firewall,

- Networking and benefits/advantages of networking, Wired (twisted pair cable ,Co-axal, optical

fiber)and wireless media(radio waves, microwaves, infrared waves, Bluetooth , satellite lnk, network

devices( Modem, Network interface card, Hub, Repeater , bridge and Gateway)network protocols-HTTP,

TCP/IP, PPP ,Inter space, Switching techniques- Message ,circuit, Packet.

Informatics Practices

Explore the following topics and present a handwritten report.

1. OPEN SOURCE CONCEPTS -Free software, open source software, FLOSS, proprietary software,

freeware, FSF, ASCII, ISCII, Unicode, Entering of Indian Scripts using phonetic method and key mapping

method.

2.COMPUTER NETWORKING- Networking and benefits/advantages of networking, Wired (twisted pair

cable ,Co-axal, optical fiber)and wireless media(radio waves, microwaves, infrared waves, Bluetooth ,

satellite lnk, network devices( Modem, Network interface card, Hub, Repeater and Gateway)network

protocols-HTTP, TCP/IP, PPP

BIOLOGY

Q.1. Which is a better mode of reproduction: sexual or asexual? Why?

Q.2 Draw the sketches of a zoospores and a conidium. Mention two dissimilarities between them and at

least one feature common to both structures.

Q.3 In haploid organisms that undergo sexual reproduction, name the stage in the life cycle when

meiosis occurs. Give reasons for your answer.

Q.4. Is there a relation between the size of an organism and its lifespan ? Give two examples in support

of your answer.

Q.5 . Why is the offspring formed by asexual reproduction referred to as clone?

Q.6 What is vegetative propagation? Give two examples.

Q.7. Define-

(a) Juvenile phase

(b) Reproductive phase

(c) Senescent phase

Q.8 Explain why meiosis and gametogenesis are always interlinked?

Q.9. Define external fertilisation. Mention its disadvantages.

Q.10. Differentiate between a zoospore and a zygote.

Q.11 Describe the post-fertilisation changes in a flower.

Q.12. Why are offspring of oviparous animals at a greater risk as compared to offspring of viviparous

animals?

Q.13. Differentiate between microsporogenesis and megasporogenesis . Which type of cell division

occurs during these events? Name the structures formed at the end of these two events.

Q.14. With a neat labelled diagram , describe the parts of a typical angiosperm ovule.

Q.15. What is meant by monosporic development of female gametophyte?

Q.16. With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte.

Q.17. What are chasmogamous flowers? Can cross-pollination occur in cleistogamous flowers? Give

reasons for your answer.

Q.18. Mention two strategies evoved to prevent self-pollination in flowers.

Q.19. What is self-incompatibility? Why does self-pollination not lead to seed formation in self-

incompatible species?

Q.20. What is bagging technique? How is it useful in a plant breeding programme?

Q.21. What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.

Q.22. Differentiate between:

(a) hypocotyl and epicotyle

(b) coleoptiles and coleorrhiza

(c) integument and testa

(d) perisperm and pericarp

Q 23. Which are the three cells found in a pollen grain when it is shed at the three-celled stage ?

Q.24. Name the component cells of the ‘egg apparatus’ in an embryo sac.

Q .25 In case of polyembryony, if an embryo develops from the synergids and another from the nucellus,

which is haploid and which is diploid ?

Q.26. How can polyembryony be commercially exploited ?

Q.27. Why is apple called a false fruit? Which part(s) of the flower forms the fruit?

Q.28. What is apomixes and what is its importance?

Q.29. Draw a labelled diagram of male reproductive system.

Q.30. Draw a labelled diagram of female reproductive system.

Q.31. Write two major functions each of testis and ovary.

Q.32. Describe the structure of a seminiferous tubules.

Q.33. What is spermatogenesis? Briefly describe the process of spermatogenesis.

Q.34. Name the hormones involved in regulation of spermatogenesis.

Q.35. Draw a labelled diagram of sperm.

Q.36. What are major functions of male accessory ducts and glands?

Q.37.What is oogenesis? Give a brief account of oogenesis.

Q.38. Draw a labelled diagram of a section through ovary.

Q.39.Name the functions of the following:

(a) Corpus Lutenum

(b) Endometrium

(c) Acrosome

(d) Sperm tail

(e) Fimbriae

Q.40. What is menstrual cycle? Which hormones regulate menstrual cycle?

Q.41. What is parturition? Which hormones are involved in induction of parturition?

Q .42 Why are menstrual cycles absent during pregnancy ?

Q . 43 What is the difference between a primary oocyte and a secondary oocyte ?

Q.44 Mention the importance of LH surge during menstrual cycle.

Q .45. What is the significance of epididymis in male fertility ?

Q.46. What is the role of cervix in the human female reproductive system ?

Q47. Which type of cell division forms spermatids from the secondary spermatocytes ?

Q.48. In our society the women are often blamed for giving birth to daughters, Can you explain why this

is not correct?

Q.49. What do you think is the significance of reproductive health in a society?

Q.50 Amniocentesis for sex determination is banned in our country. Is this ban necessary? Comment.

Q.51. Suggest some methods to assist infertilecouples to have children.

Q.52 Describe the various methods of birth control.

Q.53. What is MTP? When does Government of India legalise MTP ? How can this technique be

misused?

GEOGRAPHY

i) Map work (given in the class) to be done.

ii) Attempt the questions at the end of the chapters done so far.

Political science

Define the following concepts

a) Second world

b) Shock therapy

c)Perestroika and Glasnost

d) CIS

e) Unipolar world

f) Warsan Pact

g) NATO, SEATO, CENTO

Q2. Bring information on Mikhail Goabachev and Boris Yeltsin (write in 100 words) about each. Find about their role in the disintegration of the USSR

Q3. Trace the map given on page 24 or download a map of Soviet Union prior to its disintegration and mark its 15 republics

Q4. Make a list of Arms control and disarmament treaties signed by the US and former USSR. Write about each in brief.

Q5. Write a report on Non-aligned movement, its origin, founding leaders, difference between NAM and neutrality and NAM and isolationism, its relevance in the present day world.

Mathematics

Worksheet-I(summer holidays) (Relation& function) .Q.1Let N be the set of natural numbers and let R be the the relation on

N×N defined by (a,b) R (c,d) ⇔ ad(b+c)=bc(a+d) for all (a,b), (c,d) ∈ N×N. then show that R is an equivalence Relation.

Q.2 Show that the relation R on the set x∈Z, given by R=

( ) 5..:, multipleofaisbaba − is an equivalence relation. Also write its

equivalence classes.

Q.3 Prove that If R and S are two equivalence relations on a set A, and then SR I is also an equivalence relation on A.

Q.4Show union of two equivalence relation on a set A is not necessarily an equivalence relation on A.

Q5 Show that the signum function f: R→R is neither one one nor onto.

Q.6 Let f: N→N be defined by

−

ifnisevenn

ifnisoddn

2

2

1

show that the function is many

one onto.

Q.7Let f: W →W be defined by

−+

ifnisoddn

ifnisevenn

,1

,1 show that the function is many

one onto.

Q.8 Let f be the greatest integer function and g be the modulus function find gof (-5/3) –fog (-5/3).

Q.9 Let f:

−→

−

5

3

5

7RR be defined as f(x)=

75

43

−+

x

x and g:

−

5

3R →R-

5

7 be

defined as f(x)=35

47

−+

x

x show that fog= AI and gof = BI .

Q.10 Consider f: R→R given by f(x) = xx +3 show that f is invertible. Find

inverse of it?

Q 11 Let f: Q→Q then find ( ) ( )5,3 11 −−− ff where f(x) = 352 ++ xx

Q.12 Check whether the relationR1on R defined by R= ( ) 3:, baba ≤ is reflexive,

symmetric or transitive.

Q.13 if f(x) =12

1

+x ,x ≠

2

1 then find f(f(x)) .

Q.14 If R= ( ) 82:, =+ yxyx is a relation on N ,Write the range of R.

Q.15 If the function f : R →R be given by ( ) 22 += xxf and g: R →R be given by

g(x)=1−x

x,x 1≠

Find gof and fog and hence find fog(2) and gof(-3).

Q.16consider f: R Y→+ given by f(x) = wherexx ,569 2 −+ .,569: 2 +∈−+=∈= RxxxyRyY show that f is invertible, find

f 1− .

Q.17Let f: N R→ be a function defined as f(x)= .15124 2 ++ xx show that f : RangeN → of f is invertible. Find the inverse of f

Q.18 On the set A=w x w a binary operation * is defined by (a,b)*(c,d) =(a+c,b+d) for all (a,b),(c,d) ∈ A Discuss the commutativity as well as associativity of the binary operation* on A. Find the identity element of * on A , which elements of A are invertible? Find them.

Q.19On the set R--1 a binary operation * is defined by a*b=a+b-ab for all a,b ∈ R--1. Discuss the commutative as well as associativity of the binary operation* on R--1. Find the identity element of * on R--1 , which elements of R--1 are invertible

Q20.Define a binary operation * on a set A=1,2,3,4,5,6 as a*b=ab(mod 7) by making composition table (i) Is * commutative (ii) is * associative (iii) find identity (iv) existence of inverse

Q21.Find fog and gof if (i) f(x)= xe , g(x)= xelog (ii) f(x)= 22 +x , g(x)=x−

−1

11 .

Q22. if f(x) = ( )nnxa1

− where a 0f and n N∈ Show that f(f(x)) =x

Worksheet-I(summer holidays) (inverse circular function)

1. Solve the equation )0(,tan2

1

1

1tan 11

fxxx

x −− =

+−

2. Solve the equation ( ) ( ) xxxx 3tantan1tan1tan 1111 −−−− =+−++

3. Prove that ( )

22

1cot

2

1tan

21

21 π=

−+− −−

x

x

x

x

4. Simplify (i)

+− xx sin5

4cos

5

3cos 1 (ii) 10,

11

11tan 1 ≤≤

−++−−+− x

xx

xx

(iii)

−+−

xbxa

xbxa

sincos

cossintan 1

5. Show that ( )( )

ba

bxxa

bx

xa

ba

bx

ba

xa

−−−

=−−=

−−=

−− −−−− 2

sin2

1cotsincos 1111 .

6. Prove that 3

22sin

4

9

3

1sin

4

9

8

9 11 −− =−π. 7. Prove

that( )( )

++=

+− −−

θθθcos

coscos

2tantan2 11

ba

ba

ba

ba.

8. If ovethatcba Pr,tantantan 111 π=++ −−− a+b+c=abc. 9. Solve

( )( )

( )( ) 42

1tan

2

1tan 11 π=

+++

−− −−

x

x

x

x

10 simplify (i)2

1tan

21 xx +−− (ii) ax

ax

af,cot

22

1

−− (iii) ( )xx −+− 21 1cot (iv)

,61

5tan

21

x

x

−−

11. Prove thata

b

b

a

b

a 2cos

2

1

4tancos

2

1

4tan 11 =

−+

+ −− ππ.

12. Find the value of 2

−

−+

− −−−

3

1tan6

2

1cos3

2

1sin 111 .

13. Find the value of (i)

−−

45

1tan2tan 1 π

(ii)

−

3

5cos

2

1tan 1 (iii)

−

4

7tancot 1 π

.

14. If θ=++ −−

b

y

a

x 11 coscos Prove that θθ 22

2

2

2sincos2 =+−

b

y

ab

xy

a

x

15. Prove that cosec ( )( )( ) [ ] 13sinseccotcostan 2111pawhereaa −=−−− .

16. Evaluate

++

−−

3

2sinsin

3

2coscos 11 ππ

17. Prove that

=

+

−−−

17

31tan

7

1tan

2

1tan2 111 .

18. Solve for x ( ) ( )

=−++ −−−

31

8tan1tan1tan 111 xx .

19 Solve

−−

4cotcot 1 π

20 if4

tantan 11 π=+ −− yx then write the value of x+y+xy

20 Prove that431

17tan

5

3sin2 11 π=

−

−− . 21 Solve for x ( ) ( )xxx 111 cos1sinsin −−− =−+ .

22 Prove that

+−= −−

x

xx

1

1cos

2

1tan 11 .

23. Discuss the continuity of greatest Integer function.

24. If f(x) =

=

≠

0,0

0,1

sin

x

xx

x then discuss the continuity of f(x) at x=0.

25.If f(x) =

=

≠

0,0

0,1

cos

x

xx

x then discuss the continuity of f(x) at x=0.

26If f(x) =

=

≠+

−

0,0

0,

1

11

1

x

x

e

e

x

x

then discuss the continuity of f(x) at x=0.

27 Discuss the point of discontinuity of f defined by

f(x) =

≥+≤≤−−

≤+

326

332

33

xifx

xifx

xifx

PLESE DO THIS ASSIGNMENT IN A THICK REGISTER WHICH WILL BE LATER USED AS

TEST COPY .