HOLIDAY HOME WORK CHEMISTRY CLASS-XII homework class xii science.pdf · HOLIDAY HOME WORK CHEMISTRY CLASS-XII 1. Prepare a chemistry project of minimum 20 pages on any one of following

HOLIDAY HOME WORK

CHEMISTRY

CLASS-XII

1. Prepare a chemistry project of minimum 20 pages on any one of following.

a) Imperfection in solid

b) Polymer

c) Adsorption

d) Drugs and Medicines

e) Soap and Detergent

f) Proteins

g) Carbohydrates

h) Nucleic acid

i) Purification of Metals

j) Crystal field theory

k) Food adulterants

l) Catalysis

m) Colloidal solution

2. Solve all NCERT in text and back exercise questions of solid state, solution and electro chemistry in fair

note book

3. Do practice of IOPAC naming of organic compounds.

BIOLOGY

CLASS-XII

1. Go through the topics done in the class and learn them.

2. Ans. the following questions in neat handwriting in your holiday home work note book.

Q.1 What are chasmogamous flowers? Can cross pollination occure in cleistogamous flowers? Give reasons

for your answer.

Q.2 What is corpus luteum? Give its function.

Q.3 What is atresia?

Q.4 Define demography?

Q.5 With the help of internet prepare a project report on ARTs.

HOLIDAY HOME WORK FOR CLASS – XII

MATHEMATICS

1. Find �� when: (i) y = �� (ii) � = �� log (iii)� = �� + √� + .

2. If y =��, prove that: �1 − �� + � = 0. 3. Find �� when y = √�!�√��!"#√�#�!# .

4. Find �� when y = $%&��'�( ��'�( �.

5. Prove that; �� = )�� ), when x = � *+%� ) + $%& ,)�� -�,. and y = � �� ).

6. If x = /'�( �-and y = /(01 �-; prove that: �� = − � 234�� 234�.

7. Find ��at t = 2, when x = �5-�-# and y= !��-#��-# . 8. If x =

�� --# and y = 6� �� -- ; prove that; � �� −27��8�

= 1.

9. If y = 9:9;:9:�9;: , then show that: �� = 1 − ��.

10. Find �� when y = �� 7√��√��8 + �/+�� 7√��√��8.

11. Find �� when y = )��/+ + )�� .

12. Find �� when y = )�� 7 �√��#��8.

13. Differentiate w.r.t. :+%��2�� + ��2�� . 14. Find �� when y = )�� 7 ��#8 + +%�� 7��#

��#8.

15. If y = �√!#�5# )�� >�!5!�5 )�� ?, prove that: �� = �!�5 '�( �.

16. If y = x sin y, prove that: �� = �� '�( �.

17. If )�� 7�#��#�#�#8 = �, prove that: �� = ��-!1 !��-!1 !� = ��.

18. If y =�� >2)��?, find ��.

19. If y =�� >)��? prove that: �� = − ��.

20. If �� = �� + ��, prove that: �� = (01#�!��(01 ! . 21. If +%� � = +%�� + ��, prove that: �� = '�(#�!��(01 ! . 22. If �� + �� + �� +%�� + �� = 0, prove that: �� = ��2��+�� . 23. If A√ � + 1B� = $%&A√ � + 1− B, prove that:� � + 1� �� + � + 1 = 0. 24. If � = /��, prove that: �� = �� #. 25. If �� = /�� , prove that: �� = �� #�� . 26. If � = )�� + �/+ , prove that: �#��# = D3E��(01 ��#.

27. If� = $%&A + √ � + 1B, prove that � � + 1�� + �� = 0. 28. If� = )�� , find�2�� 2 in terms of � alone. 29. If� = )�� , then show that �1 + �� #��# + 2 �� = 0. 30. If� = A√ + 1 + √ − 1BF, then prove thatA 2 − 1B �2�� 2 + �� = G2�4 .

31. If� − �� +�� − I�� = +�, then prove that J�7KLK:8#MN/#�2�� 2

is a constant independent of a & b. 32. If = 2+%�P − +%�2P and� = 2��P − ��2P find �#��# at P = QR. 33. If � = /�!�+%��I + +�, show that: �#��# + 2� �� +�� + I�� = 0. 34. If� = )�� 7! '�( ��5 (01 �5 D3E�! EST �8,�� + I�� ≠ 0, show that �� = −1 without making any substitution. 35. If � = �� + $%&� ��, find ��. 36. Differentiate )�� 7 ��#8 w.r.t. �� 7 ��#8. 37. Find the derivative of )�� V�1+ 2−1 W w.r.t. )�� 7 ��#8. 38. If y =3/�� + 2/6�, then prove that; �#��# − 5 �� + 6� = 0. 39. If � + �� = $%& �, find�� . 40. Find the derivative of +%�� 76'�(��R(01�[ 8. 41. If \ = ] 2 2−3 14 0^ and _ = ]6 21 30 4^, find the matrix C such that A + B + C is a null matrix. 42. Construct a 3 X 4 matrix A = [aij] 3x4, whose elements are given by aij = I – 3i + j I. 43. Write the value of x – y + z from the equation] + � + ` + `� + ` ^ = ]957^. 44. If \ = c 1 0−1 7d, then find k such that,\� − 8\ + fg = h. 45. If \ = ]1 2 22 1 22 2 1^, verify that; \� − 4\ − 5g = h. 46. If \ = V 0 −)��i/2)��i/2 0 W and I is the identity matrix of order 2, then show that; g + \ = �g −

\� c+%�i −��i��i +%�i d. 47. If A is a square matrix such that A2 = A, then show that; (I + A)3 = 7A + I. 48. If \ = _ are two matrices such that \_ = _ and _\ = \, then prove that \� + _� = \ + _. 49. If for any two square matrices AB = BA, then using Principle of Mathematical Induction, prove that

(AB)n = A

nB

n. 50. If\ = c+%�i −��i��i +%�i d and A + AT

= I, then the value of α. 51. If \ = ]1 2 22 1 −2 2 � ^ is a matrix satisfying AAT

= 9I, then find the value of x and y.

52. If A and B are symmetric matrices, then prove that AB + BA is a symmetric matrix. 53. If A and B are symmetric matrices, then prove that AB – BA is a skew-symmetric matrix. 54. Express the matrix, A= ]2 4 −67 3 51 −2 4^ as the sum of symmetric and skew symmetric matrices. 55. For the matrix \ = c3 17 5d, find a and b such that A2 + aI = bA. 56. If possible, using elementary transformation, find the inverse of matrix; \ = ] 1 2 32 5 7−2 −4 −5^. 57. Find D–1, if it exists and given, = c10 −2−5 1 d ; using elementary transformations. 58. If possible, using elementary transformation, find the inverse of matrix\ = ]2 −1 3−5 3 1−3 2 3^. 59. Find the value of x, if; j1 1k ] 1 3 22 5 115 3 2^ ]

12 ^ = h. 60. Find the value of x – 2y + 3, if; 2 V 57 � − 3W +c3 41 2d = c 7 1415 14d. 61. Given that,\ = c 4 02 5 d and _ = c 03 −1d, such that AB = BA. Form an equation in x and show that it reduces to 2x2 + 17x – 12 = 0. 62. How many different matrix products can be formed with the following matrices? Also find these products. \ = j5 2k, _ = ]341^ and l = c−1 3 −12 1 4 d. 63. Prove by Principle of Mathematical Induction that (AT )n = (An)T, where � ∈ n for any square matrix A. 64. If\ = ] 1 0 20 2 1−3 1 3^ , then prove that; A3

– 6 A2 + 7A + 2I = O. Also use this result to find A–1. 65. Show that if \ = ] 3 −2 �� 3P−7 8 +%� 2P−11 14 2 ^ is a singular matrix, then: sin θ = 0 or ½.

66. Find the equation of line joining P (11, 7) and Q (5, 5) using determinants. Also find the value of k, if R (–1, k) is the point such that the area of ∆PQR is 9 sq m.

67. Show that the points (a + 5, a – 4), (a – 2, a + 3) and (a, a) do not lie on a straight line for any value of a. 68. If A is a matrix of order 3 and|\| = 4, then find the value of |��p�\�|. 69. If\ = c1 −12 −1d, _ = c� 1I 1dand�\ + _�� = \� + _�, then find the values of a and b. 70. For what value of k, the following system of linear equations have no unique solution: + � + ` =2,2 + � − ` = 2,3 + 2� + f` = 4. 71. Find k, if the points�f + 1, 1�, �2f + 1, 3� and�2f + 2, 2f� are collinear. 72. If, 218 , = , 6 218 6,, then find the value of x. 73. Using properties of determinants, prove that:

I. q + 1 + 2 + � + 2 + 3 + I + 3 + 4 + +q = 0, where a, b and c are in AP. II. q � I +� − I I − + + − �I + + + + � � + Iq = �6+I6++6 − 3�I+. III. q1 + � 1 11 1 + I 11 1 1 + +q = �I+ 7�! + �5 + �' + 18. IV. Without expanding prove that �� − I� is a factor of the determinantq1 � ��1 I I�1 + +�q;. V. Evaluate q 0 �I� �+��I 0 I+��I I�+ 0 q. 74. If = −4 is a root of the equation q 2 31 13 2 q = 0, then find the other two roots. 75. If x, y and z are different and r � 1 + 6� �� 1 + �6` `� 1 + `6r = 0, prove that �` = −1. 76. Compute�\_��, if\ = ]1 1 20 2 −33 −2 4 ^ and _�� = ]1 2 00 3 −11 0 2^. 77. Find the product of ]−4 4 4−7 1 35 −3 −1^ ]1 −1 11 −2 −22 1 3^ and then use it to solve the system of equations,

− � + ` = 4, − 2� − 2` = 9,2 + � + 3` = 1. 78. If \ = ] 1 2 1−1 1 11 −3 1^, then find \�� and hence solve the system of equations, + 2� + ` = 4, − + � + ` = 0, − 3� + ` = 4. 79. Using matrix method solve the following system of equations: − � + 2` = 0, − � + ` = −2,2 − 3` = 10 80. The sum of three numbers is 6. If we multiply third number by 3 and add second number to it, we get 11. By adding first and third numbers, we get double of second number. Represent this algebraically and find the numbers using matrix method. 81. A diet is to contain 30 units of vitamin A, 40 units of vitamin B and 20 units of vitamin C. Three types of food P, Q and R are available. 1 unit of food P contains 3 units of vitamin A, 2 units of vitamin B and 1 unit of vitamin C. 1 unit of food Q contains 1 unit of vitamin A, 2 units of vitamin B and 1 unit of vitamin C. 1 unit of food R contains 5 units of vitamin A, 3 units of vitamin B and 2 units of vitamin C. Represent this algebraically and find the numbers using matrix method. Why a proper diet is essential for us?

1. The given graph shows the variation of charge q versus potential difference V for two capacitors C

two capacitors have same plate separation but the plate area of C

in the graph correspond to C1 and

2. The electric field and electric potential at any point due to a point charge kept in air is 20 NC

respectively. Compute the magnitude of this charge.

3. An electric dipole of length 10 cm having charges ± 6 x 10

field, experiences a torque of magnitude

(i) the magnitude of the electric field.

(ii) the potential energy of the dipole.

4. Two capacitors of capacitances 6 µF and 12 µF are connected in series with a battery. The voltage across the 6

µF capacitor is 2 V. Compute the total battery voltage.

5. A parallel plate capacitor with air between the plates has a capacitance of 8 pF. The se

plates is now reduced by half and the space between them is filled with a medium of dielectric constant 5.

Calculate the value of capacitance of the capacitor in the second case.

6. A point charge 'q' is placed at 0 as shown in the figur

(i) Is VP – VQ positive or negative when (i) q > 0,

(ii) q < 0 ? Justify your answer.

7. Define 'dielectric constant' of a medium. Briefly explain why the capacitance of a parallel plate capacitor

increases, on introducing a dielectric medium between the plates

8. Draw equipotential surfaces and corresponding electric field lines for the following:

(i) Single point charge q < 0

(ii) Uniform electric field.

9. (a) Why does the electric field inside a dielectric decrease when it is placed in ail external electric field?

(b) A parallel plate capacitor with air between the plates has a capacitance of 8 pF. What will be the capacitance

if the distance between the plates be reduced by half and the space between them is filled with a substance of

dielectric constant K = 6?

10. Three point charges of +2 µc, -3 µc and

triangle of side 20 cm as shown in the figure. What should be the sign and magnitude of the charge to be placed

at the mid-point (M) of side BC so th

11. Define electric field intensity. Write its S.I. unit. Write the magnitude and direction of electric field intensity due

to an electric dipole of length 2a at the mid

Holiday Homework : 2013-14

Physics XII

shows the variation of charge q versus potential difference V for two capacitors C

two capacitors have same plate separation but the plate area of C2 is double than that of C

and C2 and why?

The electric field and electric potential at any point due to a point charge kept in air is 20 NC

respectively. Compute the magnitude of this charge.

An electric dipole of length 10 cm having charges ± 6 x 10-3

C, placed at 30° with respect to a uniform electric

field, experiences a torque of magnitude 6√3 Nm. Calculate:

the magnitude of the electric field.

the potential energy of the dipole.

Two capacitors of capacitances 6 µF and 12 µF are connected in series with a battery. The voltage across the 6

µF capacitor is 2 V. Compute the total battery voltage.

A parallel plate capacitor with air between the plates has a capacitance of 8 pF. The se


Calculate the value of capacitance of the capacitor in the second case.

A point charge 'q' is placed at 0 as shown in the figure.

positive or negative when (i) q > 0,

q < 0 ? Justify your answer.

Define 'dielectric constant' of a medium. Briefly explain why the capacitance of a parallel plate capacitor

increases, on introducing a dielectric medium between the plates.

Draw equipotential surfaces and corresponding electric field lines for the following:

(a) Why does the electric field inside a dielectric decrease when it is placed in ail external electric field?

A parallel plate capacitor with air between the plates has a capacitance of 8 pF. What will be the capacitance


3 µc and -3 µC are kept at the vertices A, B and C respectively of an equilateral


point (M) of side BC so that the charge at A remains in equilibrium?

Define electric field intensity. Write its S.I. unit. Write the magnitude and direction of electric field intensity due

to an electric dipole of length 2a at the mid-point of the line joining the two charges.

shows the variation of charge q versus potential difference V for two capacitors C1 and C2. The

is double than that of C1. Which of the lines

The electric field and electric potential at any point due to a point charge kept in air is 20 NC-1

and 10 JC-1

C, placed at 30° with respect to a uniform electric

Two capacitors of capacitances 6 µF and 12 µF are connected in series with a battery. The voltage across the 6

A parallel plate capacitor with air between the plates has a capacitance of 8 pF. The separation between the


Define 'dielectric constant' of a medium. Briefly explain why the capacitance of a parallel plate capacitor

(a) Why does the electric field inside a dielectric decrease when it is placed in ail external electric field?

A parallel plate capacitor with air between the plates has a capacitance of 8 pF. What will be the capacitance


3 µC are kept at the vertices A, B and C respectively of an equilateral


Define electric field intensity. Write its S.I. unit. Write the magnitude and direction of electric field intensity due

12. A parallel plate capacitor is to be designed with a voltage rating I kV using a material of dielectric constant 3 and

dielectric strength about 107 Vm

-1. For safety, we would like the field never to exceed say, 10% of the dipole

strength. What minimum area of the plates is required to have a capacitance of 50 pF?

13. A 4 µF capacitor is charged by a 200 V supply. The supply is then disconnected and the charged capacitor is

connected to another uncharged 2 µF capacitor. How much electrostatic energy of the first capacitor is lost in

the process of attaining the steady situation?

14. A charge q is placed at the centre of the line joining two equal charges Q. Show that the system of three charges

will be in equilibrium if q = - Q/4.

15. A 5 µF capacitor is charged by a 100 V supply. The supply is then disconnected and the charged capacitor is

connected to another uncharged 3 µF capacitor. How much electrostatic energy of the first capacitor is lost in

the process of attaining the steady situation?

16. Two fixed point charges + 4 e and + e units are separated by a distance 'a'. Where should the third point charge

be placed for it to be in equilibrium?

17. Two point charges + 10 µC and - 10 µC are separated by a distance of 40 cm in air.

(i) Calculate the electrostatic potential energy of the system, assuming the zero of the potential energy to

be at infinity.

(ii) (ii) Draw an equipotential surface of the system.

18. X and Yare two parallel plate capacitors having the same area of plates and same separation between the plates.

X has air between the plates and Y contains a dielectric medium of εr = 5.

(i) Calculate the potential difference between the plates of X and y.

(ii) What is the ratio of electrostatic energy stored in X and Y?

19. The flux of the electrostatic field, through the closed spherical surface s′ is found to be four times that through

the closed spherical surface S. Find the magnitude of the charge Q.

Given: u� = 1vl, u� = −2vl and u6 = 9.854vl

20. Find the ratio of the potential differences that must be applied across the (i) parallel, (ii) series combination of

two identical capacitors so that the energy stored, in the two cases, becomes the same.

21. An electric dipole of length 4 cm, when placed with its axis making an angle of 60° with a uniform electric field

experiences a torque of 4√3 Nm. Calculate the (i) magnitude of the electric field (ii) potential energy of the

dipole, if the dipole has charges of ± 8 nC.

22. Name the dielectric whose molecules have (i) non-zero, (ii) zero dipole moment. Define the term 'dielectric

constant' for a medium.

23. Write the ratio of the (i) charges on the plates, when two capacitors, of capacitances C1 and C2, are put in series.

(ii) Potential differences, between the plates, when two capacitors of capacitances C1 and C2, are put in parallel.

Give also the ratio of the equivalent capacitances of the series and parallel combinations of these two

capacitors.

24. Mention any two properties of electric lines of force. Sketch them for an isolated positive point charge.

25. What is an electric line of force? Sketch lines of force due to two equal positive charges placed at a small

distance apart in air.

26. State Gauss' theorem in electrostatics. Using this theorem, prove that no electric field intensity exists inside a

hollow charged conducting sphere.

27. Show mathematically that potential at a point on the equatorial line of an electric dipole is zero.

28. Two similarly and equally charged identical metal spheres A and B repel each other with a force of 2

third identical uncharged sphere C is touched with A and then placed at the mid

Calculate the net electric force on C.

29. State Gauss's theorem in electrostatics. A charge of 17.7 x 10

area 200 m2. Calculate the electric field intensity at a distance 20 cm from it in air.

30. Electric field intensity at point 'B' due to a point charge 'Q' kept at point 'A' is 24 NC

point 'B' due to same charge is 12 JC

31. 2-μC charge is placed at each comer of a square ABCD of side 2

O of the square.

32. Two rectangular metal plates, each of area A, are kept parallel to each other at a distance’d’ apart to form a

parallel plate capacitor. If the area of each of the plates is doubled and their distance of separation decreased to

1/2 of its initial value, calculate the ratio of their capacitances in the two cases.

33. Two point charges of +3 × 10-8

C and

joining these charges the electric potential is zero. Take potential at infinity to be

34. S1 and S2 are two hollow concentric sphere

(i) What is the ratio of the electric flux through S

(ii) How will the electric flux through the sphere S

introduced in the space inside S

35. An electric dipole is free to move in a uniform electric field. Explain its motion when it is placed (i) parallel to the

field, and (ii) perpendicular to the field.

36. Two identical metallic spheres, having unequal, opposite charges are placed at a distance 0.90 m apart in air.

After bringing them in contact with each other, they are again placed at the same distance apart. Now the force

of repulsion between them is 0.025 N. Calculate the final charge on each of them.

37. Find the ratio of linear momenta acquired by an α

potential.

38. Two equal charges of + 2 × 10-16

C are kept 20 cm apart in air. At a point midway between th

field intensity and (ii) force acting on a charge of + 2 × 10

39. Four point charges of qA = 2 µC, qB

of side 10 cm, Find the force on a charge of 1 μC pl

Two similarly and equally charged identical metal spheres A and B repel each other with a force of 2

third identical uncharged sphere C is touched with A and then placed at the mid

Calculate the net electric force on C.

State Gauss's theorem in electrostatics. A charge of 17.7 x 10-4

C is distributed uniformly over a

. Calculate the electric field intensity at a distance 20 cm from it in air.

Electric field intensity at point 'B' due to a point charge 'Q' kept at point 'A' is 24 NC-1

and the electric potential at

s 12 JC-1

. Calculate the distance AB and also the magnitude of charge Q.

μC charge is placed at each comer of a square ABCD of side 22√2 cm. Calculate electric potential at the centre

Two rectangular metal plates, each of area A, are kept parallel to each other at a distance’d’ apart to form a


lculate the ratio of their capacitances in the two cases.

C and -2 × 10-8

C are located 15 cm apart in air. Find at what point on the line

joining these charges the electric potential is zero. Take potential at infinity to be zero.

are two hollow concentric sphere-enclosing charges Q and 2Q respectively as shown in the figure.

What is the ratio of the electric flux through S1 and S2?

How will the electric flux through the sphere S1 change, if a medium of dielectri

introduced in the space inside S1 in place of air?

An electric dipole is free to move in a uniform electric field. Explain its motion when it is placed (i) parallel to the

field, and (ii) perpendicular to the field.

Two identical metallic spheres, having unequal, opposite charges are placed at a distance 0.90 m apart in air.


5 N. Calculate the final charge on each of them.

Find the ratio of linear momenta acquired by an α -particle and a proton accelerated through the same

C are kept 20 cm apart in air. At a point midway between th

field intensity and (ii) force acting on a charge of + 2 × 10-16

C.

= -5 μC, qC = 2 μC, and qD = -5 μC are located at the comers of a square ABCD

of side 10 cm, Find the force on a charge of 1 μC placed at the centre O of the square.

Two similarly and equally charged identical metal spheres A and B repel each other with a force of 2 x 10-5

N. A

third identical uncharged sphere C is touched with A and then placed at the mid-point between A and B.

C is distributed uniformly over a large sheet of

and the electric potential at

. Calculate the distance AB and also the magnitude of charge Q.

cm. Calculate electric potential at the centre

Two rectangular metal plates, each of area A, are kept parallel to each other at a distance’d’ apart to form a


C are located 15 cm apart in air. Find at what point on the line

zero.

enclosing charges Q and 2Q respectively as shown in the figure.

change, if a medium of dielectric constant 5 is

An electric dipole is free to move in a uniform electric field. Explain its motion when it is placed (i) parallel to the

Two identical metallic spheres, having unequal, opposite charges are placed at a distance 0.90 m apart in air.


particle and a proton accelerated through the same

C are kept 20 cm apart in air. At a point midway between them find (i) electric

5 μC are located at the comers of a square ABCD

40. What is an equipotential surface? Show that no work is done in moving a test charge from one point to another

over an equipotential surface.

41. Four point charges 10-8

C, -2 × 10-8

C, -4 × 10-8

C and 6 × 10-8

C are placed at the four corners of a square of side

2√2 cm. Calculate the electric potential at the centre of square.

42. The electric field intensity and potential at a point due to a point charge are 36 N/C and 18 J/C respectively.

Calculate (i) magnitude and (ii) position of the charge from the point.

43. A proton is moved in a uniform electric field of 1.7 × 10-4

N/C between two points A and B separated by a

distance of 0.1 m.

(i) What is the potential difference between the points?

(ii) How much work is done in the above process?

44. A spherical Gaussian surface encloses a charge of 8.85 × 10-8

C.

(i) Calculate the electric flux passing through the surface.

(ii) If the radius of the Gaussian surface is doubled, how would the flux change ?

45. A spherical Gaussian surface encloses a charge of 17.7 × 10-8

C.

(i) Calculate the electric flux passing through the Gaussian surface.

(ii) If the radius of the Gaussian surface is doubled, how much flux would pass through the surface?

46. Force of attraction between two point charges placed at a distance 'd' apart in a medium is 'F'. What should be

the distance in the same medium so that the force of attraction between them becomes 9F?

47. Force of attraction between two points charges placed at a distance’d’ apart in a medium is 'F'. What should be

the distance apart in the same medium so that the force of attraction between them becomes F/3?

48. A point charge 'q' is placed at 0 as shown. Is VA - VB positive, negative or zero, if 'q' is a

(i) positive,

(ii) negative charge?

49. What is an equipotential surface? Show that the electric field is always directed perpendicular to an

equipotential surface.

50. Two point charges 4 μC, - 2μC are separated by a distance of 1 m in air. At what point on the line joining the

charges is the electric potential zero.

51. Two point charges of + 3.2 × 10-19

C an + 16× 10-19

C are separated by a distance 2.5 m. Find the point on the line

joining them at which the electric field intensity is zero.

52. What is an equipotential surface? Show that the electric field at a point on the surface of charged conductor or

just outside it is perpendicular to the surface?

53. Derive an expression for the potential at a porn along the axial line of a short electric dipole.

54. A hollow conducting sphere of radius 8 cm is given a charge 161lC. What is the electric field intensity?

(i) at the centre of the sphere and

(ii) On the outer surface of the sphere.

55. Four capacitors are connected as shown in the figure given below: Calculate the equivalent capacitance between

the points X and Y.

56. An electric dipole of length 2 cm is placed with its axis making an angle of 600 to a uniform electric field of 105

N/C. If it experiences a torque of 8√3 Nm, calculate the :

(i) magnitude of the charge on the dipole, and

(ii) potential energy of the dipole.

57. Calculate the potential at the centre of a square Y of side √4.5 m which carries at its four comers charges of + 5

× 10-9

C, 2 × 10-9

C, - 5 × 10-9

C and - 7 × 10-9

C respectively.

58. Calculate the potential at the centre of a square of side √2 m, which carries at its four comers charges of + 2 nC,

+ 1 nC, - 2 nC and - 3 nC respectively.

59. When two capacitors of C1 and C2 are connected in series the net capacitance is 3 μF; when connected in parallel

its value is 16 μF. Calculate values of C1 and C2.

60. A proton placed in a uniform electric field of magnitude 2000 N/C moves between two points in the direction of

electric field. If the distance between the points is 0.2 m, find the value of (i) p.d. between the points, (ii) work

done.

61. Define the term 'electric field intensity. Electric field inside a conductor is zero. Explain.

62. Two point charges A and B of value + 5 × 10-9

C and + 3 × 10-9

C are kept 6 cm apart in air. Calculate the work

done when charge B is moved 1 cm towards charge A.

63. Two point charges A and B of value + 5 μC and + 6 μC are kept 12 cm apart in air. Calculate the work done when

charge B is moved by 2 cm towards charge A.

64. Derive an expression for the energy stored in a charged parallel plate capacitor with air as the medium between

its plates.

65. 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.

66. An electric flux of – 6 × 103 Nm

2/C passes normally through a spherical Gaussian surface of radius 10 cm, due to

point charge placed at the centre.

(a) What is the charge enclosed by the Gaussian surface?

(b) If the radius of Gaussian surface is doubled, how much flux would pass through the surface?

67. Two point electric charges A and B of 1.5 μC and 2.5 μC respectively are kept 30 cm apart in air. Calculate the

electric potential at a point C, which is 10 cm from the mid-point of straight line AB and is on a plane normal to

AB.

68. Two point electric charges of unknown magnitude and sign are placed a distance’d’ apart. The electric field

intensity is zero at a point, not between the charges but on the line joining them. Write two essential conditions

for this to happen.

69. Two point charges + 4 μC and -6 μC are separated by a distance of 20 cm in air. At what point on the line joining

the two charges is the electric potential zero?

70. Define 'intensity of electric field' at a point. At what points is the electric dipole field intensity parallel to the line

joining the charges?

71. (i) Calculate the electric potential at a point x P due to a charge of 0.5 ~C located at 10 cm from it.

(ii) Also calculate the work done in bringing a charge of 3 × 10-9

C from infinity to the point x.

******

HOLIDAY HOME WORK

ENGLISH : CLASS XII

Instructions: Holiday Home Work in separate note book

Q1. Prepare a power point presentation (ppt) of the novel “The Invisible Man” by HG Wells

(Summarising each chapter)

Q2. Prepare two charts on any two of the following topics (posters, using slogans and

proverbs)

a) Blood Donation

b) Save your Planet

c) Eye donation

d) Reckless driving

e) Drug Addiction

Q3. Write the character sketch of M Hamel (The Last Lesson)

Q4. Make notes of the chapter “The Enemy”(Vistas)

Q5. Write articles on the topics given below (200 words)

a) Lack of civic sense

b) Cruelty to animals

Q6. You are Rachit/ Rachita of 25 Green Park New Delhi. You desire to seek admission in Hyde

Management Institute, Pune. Write a letter to the Director of the Institute enquiring about the

admission procedure and other details.

Q7. Revise and learn the work done in class.

SUBJECT – COMPUTER SCIENCE WITH C++

Q1 – Make a Practical file and display the printout of 5 programs and output based on Classes

And Objects?

Q2-Make a Power Point presentation on –(i) Object Orientated Programming – Concepts

(Abstraction, Polymorphism, Inheritance, Encapsulation )

PAINTING

Draw 30 pages of sketching file : Flower, Birds, Animal, Cartoon figure etc.

PHYSICAL EDUCATION

1. A brief report on FIFA world cup tournament

2. Solve one marks questions from chapter I and II

Documents

HOLIDAY HOME WORK CHEMISTRY CLASS-XII homework class xii science.pdf · HOLIDAY HOME WORK CHEMISTRY CLASS-XII 1. Prepare a chemistry project of minimum 20 pages on any one of following