PLUS TWO PHYSICS TN STATE BOARD EXAM QUESTIONS UNIT 1 ELECTROSTATICS

To Download a PDF version CLICK HERE

Dear Students!
Following is the collection of all TN State Board Exam Questions (for Plus Two Physics) that appeared from March 2006 to September 2014. Answers for the MCQs and Problems will be uploaded soon. Pl note that the (circuit) diagrams are missing in this file; the same can be viewed in the pdf file uploaded in the same name as this file.

PLUS TWO PHYSICS TN STATE BOARD EXAM QUESTIONS UNIT – I ELECTROSTATICS
MARCH – 2006 UP TO SEP – 2014

1. The unit of electric flux is M06, J09
a] Nm2C–1 b] Nm–2C–1 c] Nm2 C d] Nm– 2 C.
2. An electric dipole is placed in a uniform electric field with its axis parallel to the field. It experiences
M06, M07, S07, J13
a] only a net force b] neither a net force nor a torque
c] both a net force and a torque d] only a torque.
3. The work done in moving a 4 μ C charge from one point to another in an electric field is 0.012 J.
The potential difference between them is M06
a] 3000 V b] 6000 V c] 30 V d] 48 x 10 3 V.
4. The electric field outside two oppositely-charged plane sheets each of charge density σ is
M06, S09, M11, J11, M13, S14
a] σ / 2ε 0 b] - σ / 2 ε 0 c] σ / ε 0 d] zero
5. Which of the following quantities is a scalar? J06, J08, M09, J10, S11, M13
a] Electric force b] Electric field c] Dipole moment d] Electric potential.
6. Torque on a dipole in a uniform electric field is maximum when the angle between p and E is J06
a] 0^0 b] 90^0 c] 45^0 d] 180^0 .
7. Potential energy of two equal negative point charges of magnitude 2 μ C placed 1 m apart in air is J06
a] 2 J b] 0.36 J c] 4 J d] 0.036 J.
8. A hollow metal ball carrying an electric charge produces no electric field at points J06, M12
a] on its surface b] inside the sphere c] at infinite distance from its centre d] outside the sphere.
9. The unit of electric field intensity is S06, S14
a] NC^–2 b] NC c] Vm^–1 d] Vm.
10. Four charges +q, +q, −q and –q respectively are placed at the corners A, B, C and D of a square of side a. The electric potential at the centre O of the square is S06
a] 1/(4πε_0 ) q/a b] 1/(4πε_0 ) 2q/a c] 1/(4πε_0 ) 4q/a d] zero
11. The value of permittivity of free space is ----------- C^2 N^–1 m^2 . S06
a] 8.854 x 10^12 b] 9 x 10^9 c] 1/(9 x 〖10〗^9 ) d] 1/(36π x 〖10〗^9 )
12. The principle used in lightning conductors is S06
a] corona discharge b] mutual induction c] self-induction d] electromagnetic induction
13. The unit of electric dipole moment is M07
a] V / m b] C / m c] V m d] C m.
14. Electric potential energy of an electric dipole in an electric field is given as M07
a] p E sin θ b] – p E sin θ c] – p E cos θ d] p E cos θ
15. Elec. field intensity is 400 Vm^−1 at a distance of 2 m from a point charge. It will be 100 Vm^−1 at a distance of M07, J12, S12
a] 50 cm b] 4 cm c] 4 m d] 1.5 m.
16. Which of the following is not a dielectric? J07
a] Ebonite b] Mica c] Oil d] Gold.
17. Work done in moving 500 μC (50 μC) charge between two points on equipotential surface is
J 07, M08, M10, J10, S11, M12, (J12), J14
a] zero b] finite positive c] finite negative d] infinite.
18. In the given circuit, the effective capacitance between A and B is J 07
a] 3 μF b] 36/13 μF c] 13 μF d] 7 μF
19. The direction of electric field at a point on the equatorial line due to an electric dipole is J 07
a] along the equatorial line towards the dipole b] along the equatorial line away from the dipole
c] parallel to the axis of the dipole and opposite to the direction of dipole moment
d] parallel to the axis of the dipole and in the direction of dipole moment
20. The number of electric lines of force originating from a charge of 1µ C is S07
a] 1.129 × 10^5 b] 1.6 × 10^−19 c] 6.25 × 10^18 d] 8.85 × 10^12
21. The equivalent capacitance of two capacitors in series is 1.5 μ F. The capacitance of one of them is 4 μF.
The value of capacitance of the other is S07
a] 2.4 μ F b] 0.24 μ F c] 0.417 μ F d] 4.17 μ F
22. The law that governs the force between electric charges is ________ law. S07
a] Ampere’s b] Faraday’s c] Coulomb’s d] Ohm’s
23. The unit of permittivity is M08, S08, J11, S12, S13
a] C^2 N^–1 m^–2 b] N m^2 C^–2 c] H m^–1 d] N C^–2 m^–2
24. An electric dipole placed at an angle θ in a non-uniform electric field experiences M08, S08
a] neither a force nor a torque b] only a torque c] both force and torque d] only a force
25. A capacitor of capacitance 6 μ F is connected to a 100 V battery. The energy stored in the capacitor is M08
a] 30 J b] 3 J c] 0.03 J d] 0.06 J
26. The unit of electric field intensity is J08
a] V m b] C N –1 c] V C –1 d] N C –1
27. When an electric dipole of dipole moment p is aligned parallel to the electric field E then the potential energy of the dipole is given as J08
a] pE b] zero c] - pE d] pE/√2
28. The capacitance of a parallel plate capacitor increases from 5 μF to 60 μF when a dielectric is filled between the plates. The dielectric constant of the dielectric is J08, J10, J14, S14
a] 65 b] 55 c] 12 d] 10
29. An example of a conductor is S08
a] glass b] human body c] dry wood d] ebonite
30. Quantisation of electric charge is given by S 08
a] q = n e b] q = c V c] q = e / n d] q = c / V
31. The unit of electric field intensity is M09
a] NC b] NC – 1 c] Vm d] NC – 2
32. The magnitude of force acting on a charge of 2 x 10 –10 C placed in a uniform electric field of 10 V m – 1 is
M09, M14
a] 2 x 10 –9 N b] 4 x 10 –9 N c] 2 x 10 –10 N d] 4 x 10 –10 N
33. Electric potential energy (U) of two point charges is M09, S12, J10, J11, S13
a] (q_1 q_2)/(4πε_0 r^2 ) b] (q_1 q_2)/(4πε_0 r) c] pE cosθ d] pE sinθ
34. The torque ( τ ) experienced by an electric dipole placed in a uniform electric field ( E ) at an angle θ with the field is J09
a] p E cos θ b] – p E cos θ c] p E sin θ d] 2 p E sin θ
35. The capacitance of a parallel-plate capacitor increases from 5 µ F to 50 µ F when a dielectric is filled between the plates. The permittivity of the dielectric is J09
a] 8.854 x 10 –12 C 2 N – 1 m –2 b] 8.854 x 10 – 11 C 2 N – 1 m –2 c] 12 d] 10.
36. The negative gradient of potential is J09
a] electric force b] torque c] electric current d] electric field intensity.
37. When a point charge of 6 µ C is moved between two points in an electric field, the work done is 1.8 x 10 – 5 J. The potential difference between the two points is S09
a] 1.08 V b] 1.08 µ V c] 3 V d] 30 V
38. The torque on a dipole in a uniform electric field is maximum when the angle between p ̅ and E ̅ is S09
a] 0^0 b] 〖45〗^0 c] 〖90〗^0 d] 〖180〗^0
39. The equivalent capacitance of two capacitors connected in series is 1.5 µ F. The capacitance of one of them is 4 µ F. The capacitance of the other is S09
a] 2.4 µ F b] 2 µ F c] 4 µ F d] 6 µ F
40. A hollow metal ball carrying an electric charge produces no electric field at points M10, J13
a] outside the sphere b] on its surface
c] inside the sphere d] at a distance more than twice its radius
41. Three capacitors of capacitances 1 µF, 2 µF and 3 µF are connected in series. The effective capacitance of the capacitors is M10
a] 6 µF b] 11/6 µF c] 6/11 µF d] 1/6 µF
42. An electric dipole of moment p ̅ is placed in a uniform electric field of intensity E ̅ at an angle θ with respect to the field. The direction of the torque is M10
a] along the direction of p ̅ b] opposite to the direction of p ̅
c] along the direction of E ̅ d] perpendicular to the plane containing p ̅ and E ̅
43. Electric field intensity at a distance r due to infinitely long straight charged wire is directly proportional to J10, S12
a] r b] 1 / r c] r 2 d] 1 / r 2
44. Ratio of electric potential at points 10 cm and 20 cm from centre of an electric dipole along its axial line is J10
a] 1 : 2 b] 2 : 1 c] 1 : 4 d] 4 : 1.
45. The intensity of electric field at a point is equal to J10
a] the force experienced by a charge q
b] the work done in bringing unit positive charge from infinity to that point
c] the positive gradient of the potential d] the negative gradient of the potential.
46. The capacitance of a capacitor is J10
a] directly prop. to the charge q given to it b] inversely prop. to its potential V
c] directly prop. to the charge q and inversely prop. to the potential V
d] independent of both the charge q and potential V.
47. The intensity of the electric field that produces a force of 10 – 5 N on a charge of 5 µ C is M11
a] 5 x 10 – 11 N C – 1 b] 50 N C – 1 c] 2 N C – 1 d] 0.5 N C – 1.
48. The unit of number of electric lines of force passing through a given area is M11
a] no unit b] N C–1 c] N m2 C–1 d] N m.
49. If a point lies at a distance x from mid-point of a dipole, the elect. potential at this point is prop. to M11
a] 1/x^( 2) b] 1/x^( 3) c] 1/x^( 4) d] 1/x^( 3/2) .
50. A dielectric medium is placed in an electric field E0 . The field induced inside the medium J11
a] acts in the direction of the electric field E0 b] acts opposite to E0
c] acts perpendicular to E0 d] is zero.
51. A non-polar dielectric is placed in an electric field E. Its induced dipole moment S11, (J14)
a] is zero (at random) b] acts in the direction of E
c] acts opposite to the direction of E d] acts perpendicular to E.
52. n capacitors each of capacitance C are connected in series. The effective capacitance is S11
a] n / C b] C / n c] nC d] C.
53. When the charge given to a conductor is doubled, its capacitance M12
a] increases twice b] decreases twice c] increases four times d] does not change.
54. The value of permittivity of air is M12
a] 8.854 x 10 – 12 C2 N– 1 m– 2 b] 9 x 10 9 C2 N– 1 m– 2 c] 1 d] 8.854 x 10 12.
55. The unit of relative permittivity is J12
a] C2N– 1m– 2 b] Nm– 2 C– 1 c] no unit d] NC– 2 m– 2 .
56. The electric field intensity at a short distance r from uniformly-charged infinite plane sheet of charge is J12
a] proportional to r b] proportional to 1/r c] proportional to 1/r^2 d] independent of r.
57. An electric dipole of dipole moment ‘p’ is kept parallel to an electric dipole of intensity ‘E’. The work done in rotating the dipole through an angle of 900 is M13
a] zero b] - pE c] pE d] 2pE.
58. Two point charges + q and – q are placed at points A and B respectively separated by a small distance. The electric field intensity at the midpoint O of AB M13
a] is zero b] acts along AB c] acts along BA d] acts perpendicular to AB.
59. The electric field inside the plates of two oppositely-charged plane sheets each of charge density σ is J13
a] σ / 2ε 0 b] - σ / 2 ε 0 c] σ / ε 0 d] zero .
60. The total flux over a closed surface enclosing a charge q ( in Nm2C–1 ) J13
a] 8πq b] 9 x 109 q c] 36π x 109 q d] 8.854 x 10 –12 q.
61. The repulsive force between two like charges of 1 coulomb each separated by a distance of 1 m in vacuum is equal to S13
a] 9 x 109 N b] 109 N c] 9 x 10―9 N d] 9 N.
62. If a point lies at a distance ‘ x ’ from the mid-point of the dipole, the electric potential at this point is proportional to M14
a] 1/x^2 b] 1/x^3 c] 1/x^4 d] 1/x^(3/2) .
63. The electric field between the plates of two oppositely-charged plane sheets of charge density σ is M14
a] + σ/(2ε_o ) b] ― σ/(2ε_o ) c] σ/ε_o d] zero.
64. What must be the distance between two equal and opposite point charges (say + q and ― q) for the electrostatic force between them to have a magnitude of 16 N? M14
a] 4√kq metre b] q/4 √k metre c] 4 kq metre d] 4k/q metre.
65. Van de Graaff generator works on the principle of J14
a] electromagnetic induction and action of points b] electrostatic induction and action of points
c] electrostatic induction only d] action of points only.
66. For which of the following medium, the value of relative permittivity is ε_r = 1 S14
a] Mica b] Air c] Glass d] Water.

PART – II 3 MARK QUESTIONS
Define ‘coulomb’ on the basis of Coulomb’s law. M06, S10, M13
Why is it safer to be inside a car than standing under a tree during lightning? M06, J06, J09, M10, J14
State Gauss’ law in electrostatics. J06, S06, M09, M11
What is meant by (di)electric polarisation? S06, S09, (S11), J14
What is a polar molecule? Give any two examples. M07, M13
Define electric potential at a point. M07, J09, J13, S13
State Coulomb’s law in electrostatics. J07, M10, J10, S11, J12
What is corona discharge? What are its advantages? (Give its applications) J07, S08, (S14)
Write the applications of capacitor. S07, M11, M12
What do you mean by ‘Additive nature of charge’ ? Give an example. S07
Three capacitors each of capacitance 9 pF are connected in series. What is the total capacitance of the combination? M08
What is electrostatic shielding? M08
Define electric flux. Give its unit. J08, J12
Explain the working of microwave oven. J08, S14
Calculate the effective capacitance of the combination shown in the fig. S08, J13
What is a capacitor? Define its capacitance. M09, S12
What is an electric dipole? Define its dipole moment. S09, J11
Mention any three properties of electric lines of force. J10
What is a non-polar molecule? Give (any two) examples. S10, J11, (S13)
Calculate the potential at a point due to a charge of 4 x 10 – 7 C located at 0.09 m away from it. M12, M14
Write any three properties of electric lines of force. S12
Define electric-dipole moment. Give its unit. M14

PART – III 5 MARK QUESTIONS
A parallel plate capacitor has plates of area 200 cm 2 and separation between the plates 1 mm. Calculate (i) the potential difference between the plates if 1n C charge is given to the capacitor (ii) with the same charge (1n C) if the plate separation is increased to 2 mm, what is the new potential difference and (iii) electric field between the plates. M06
Three capacitors each of capacitance 9 pF are connected in series (i) What is the total capacitance of the combination? (ii) What is the potential difference across each capacitor, if the combination is connected to 120 V supply? J06, S06, J11
Write the properties of lines of force. M07, S07, M08, M10, M11, S11, J11, J12, M13
a] Two capacitances 0.5 μF and 0.75 μF are connected in parallel and the combination to a 110 V battery. Calculate the charge from the source and charge on each capacitor. [ OR ]
b] A square of side 1.3 m has charges + 12 nC, - 24 nC, + 31 nC and + 17 nC at its corners. Calculate the electric potential at the centre of the square. J07 (complsry)
Two positive charges of 12 μC and 8 μC respectively are 10 cm apart. Find the work done in bringing them
4 cm closer, so that, they are 6 cm apart. J08
Two capacitors of unknown capacitances are connected in series and parallel. If net capacitances in two combinations are 6μF and 25μF respectively, find their capacitances. S08
Define electric potential at a point. Obtain an expression for electric potential due to a point charge. M09
The plates of a parallel plate capacitor have an area of 90 cm 2 each and are separated by 2.5 mm. The capacitor is charged by connecting it to a 400 V supply. How much electrostatic energy is stored by the capacitor? J09, S13
What is electrostatic potential energy of a system of charges? Deduce an expression for it. S09
Deduce an expression for the capacitance of a parallel plate capacitor. J10
Derive an exp. for torque experienced by an electric dipole when placed in a uniform electric field. S10, S12, S14
Three charges – 2 × 10 – 9 C, +3 × 10 – 9 C, – 4 × 10 – 9 C are placed at the vertices of an equilateral triangle ABC of side 20 cm (See Fig.). Calculate the work done in shifting the charges A, B and C to A1, B1 and C1 respectively which are the mid points of the sides of the triangle. J11
Prove that the energy stored in a parallel-plate capacitor is q^( 2)/(2 C) . M12
Derive an expression for the capacitance of a parallel-plate capacitor with a dielectric medium. J13
Deduce an expression for the effective capacitance of capacitors of capacitances C_1, C_2, C_3 connected in series. M14
What is a capacitor? Explain the principle of capacitor. J14

PART – IV 10 MARK QUESTIONS
What is an electric dipole? Derive an expression for the electric field due to an electric dipole at a point on its axial line. M06, J06, M09, J10, S10, M11, J14
Derive an expression for the electric potential at a point due to an electric dipole. Discuss the special cases. S06, M08, M10, S11, M13
Derive an expression for the electric field due to an electric dipole at a point on its equatorial line. M07, J09, S13
Deduce an expression for the equivalent capacitance of capacitors connected [i] in series and [ii] in parallel. J07, S07,
What is an electric dipole? Derive an expression for electric potential due to an electric dipole. J08
State the principle and explain the construction and working of van de Graaff generator.
S08, S09, S12, M14
State Gauss law. Using Gauss law, obtain an expression for the electric field due to an infinitely long straight uniformly charged wire. J11, M12, J13
Explain the principle of a capacitor. Obtain the expression for the capacitance of a parallel-plate capacitor.
J12
Explain the principle of capacitor. Deduce an expression for the capacitance of a parallel plate capacitor.
S14