1. A hollow metal sphere of radius 5 cm is charged such that the potential on its surface is 10 V. Then the potential at the centre of the sphere is ..
1) Zero 2) 10 V 3) 5 V 4) 7.5 V
2. A charge q is placed at the centre of the line joining two equal charges Q. The system of the three charges will be in equilibrium it q is equal to .. 
3. An electric dipole placed with its axis in the direction of a uniform electric field experiences ..
1) a force but no torque 2) a torque but no force
3) a force as well as a torque 4) neither a force nor a torque
4. The electric field due to an extremely short dipole at a distance r from it is proportional to .. 
5. If n drops, each of capacitance C, coalesce to form a single big drop, the capacitance of the big drop will be ..
1) n3C 2) nC 3) n1/2C 4) n1/3C
6. A parallel plate capacitor with air as dielectric is charged to a potential V. It is then connected to an uncharged parallel plate capacitor filled with wax of dielectric constant K. Then the common potential of both capacitors is ..
1) V 2) KV 3) (1 + K)V 4) V/(1 + K)
7. A charge Q is given to a hollow metallic sphere of radius R. Then the electric field at a distance r from the centre of the sphere where r < R is .. 
8. Eight dipoles of charges of magnitude q are placed inside a cube. Then the total electric flux through the cube will be .. 
9. n identical capacitors are joined in parallel and the combination is charged to a voltage V. The total energy stored is U. The capacitors are now disconnected and joined in series. Then the total energy stored in the series combination will be ..
1) U 2) U/n 3) n.U 4) n2U
10. Two spheres of radii r1 and r2 carry charges Q1 and Q2 respectively. When they are connected by a wire, there will be no loss of energy of the system if ..
1) Q1r1 = Q2r2 2) Q1r2 = Q2r1 3) Q1r12 = Q2r22 4) Q1r22 = Q2r12
11. If the potential difference between the plates of a capacitor is increased by 20%, the energy stored in the capacitor increases by ..
1) 20% 2) 40% 3) 44% 4) 80%
12. A spherical capacitor consists of a spherical conducting shell of radius a which is surrounded by a concentric outer spherical shell of radius b. Then the capacitance of the capacitor is .. 
13. A negative point charge - Q is placed at a distance r from the surface of an uncharged conducting sphere of radius R. Then the net charge on the sphere will be ..
1) zero 2) positive 3) negative 4) positive of r < R and negative if r > R.
14. The current through a bulb is increased by 1%. Assuming that the resistance of the filament remains unchanged, the power of the bulb will
1) increase by 1% 2) decrease by 1% 3) increase by 2% 4) decrease by 2%
15. Three equal resistors, connected in series with a battery, dissipate P watts of power. What will be the power dissipated if the same resistances are connected in parallel across the same battery?
1) p 2) 3p 3) 9p 4) 27p
16. A constant voltage is applied between the two ends of a metallic wire. Some heat is developed in it. The heat developed is doubled if ..
1) both length and radius of the wire are halved
2) both length and radius of the wire are doubled
3) the radius of the wire is halved
4) the length of the wire is doubled.
17. If a wire is stretched to make it 0.1% longer, its resistance will ..
1) remain uncharged 2) increase by 0.2%
3) decrease by 0.2% 4) increase by 0.1%
18. What is the maximum number of 100 W bulbs all connected is parallel with a 220 V power supply fitted with a 6 A fuse?
1) 10 2) 11 3) 12 4) 13
19. When a charged particle moves perpendicular to a uniform magnetic field, its ..
1) energy and momentum both change
2) energy changes but momentum remains unchanged
3) momentum changes but energy remains unchanged
4) both energy and momentum remains constant
20. A proton with kinetic energy K describes a circle of radius r in a uniform magnetic field. An α − particle with kinetic energy K moving in the same magnetic field will describe a circle of radius ..
1) r 2) r/2 3) 2r 4) 4r
21. The frequency of the charged particle circulating at right angles to a uniform magnetic field does not depend upon
1) speed of the particle 2) mass of the particle
3) charge of the particle 4) magnetic field
22. The angle of dip is 90° at
1) Magnetic poles 2) Magnetic equator 3) Geographic poles 4) 90° latitude
23. The relative permeability of a substance X is slightly greater than unity while that of a substance Y is slightly less than unity. Then ..
1) X is ferromagnetic and Y para magnetic
2) X is dia magnetic and Y para magnetic
3) X is para magnetic and Y dia magnetic
4) both X and Y are dia magnetic
24. A charged particle is released from rest in a region of steady and uniform electric and magnetic fields which are parallel to each other. The particle will move in a
1) straight line 2) circle 3) helix 4) cycloid
25. The magnitude of the induced emf produced in a coil when a magnet is inserted into it does not depend upon ..
1) number of turns in the coil 2) resistance of the coil
3) magnetic moment of the magnet 4) speed of approach of the magnet
26. A choke is used as a resistance in ..
1) DC circuits 2) AC circuits 3) both AC, DC circuits 4) rectifier circuits
27. An AC series circuit contains 4Ω resistance and 3Ω inductive reactance. What is the impedance of the circuit?
1) 1 Ω 2) 5 Ω 3) 7 Ω 4) 9 Ω
28. An AC source of variable frequency f is connected to an LCR series circuit. Which one of the graphs in the following represents the variation of current I in the circuit with the frequency f ?
29. A circular loop of radius R, carrying current I, lies in the x-y plane with its centre at the origin. Then the total magnetic flux through the x-y plane is ..
1) directly proportional to I 2) directly proportional to R
3) inversely proportional to R 4) zero
30. If the flux of magnetic induction through a coil of resistance R and having n turns changes from φ1 to φ2, then the magnitude of the charge that passes through the coil is .. 
31. In the circuit shown in the figure, the reading of the ammeter is (assume the internal resistance of the battery zero) 
32. An ammeter is obtained by shunting a 30Ω galvanometer with a 30Ω resistance. What additional shunt should be connected across it to double the range?
1) 5 Ω 2) 10 Ω 3) 15 Ω 4) 20 Ω
33. Which of the two switches S1 and S2 shown in the figure will produce short - circuiting?
1) S1 2) S2 3) Both S1 and S2 4) Neither S1 nor S2
34. A battery of emf ∈ and internal resistance r is connected across a pure resistive device of resistance R. The power output of the device will be maximum if ..
1) R = r 2) R = 2r 3) R = √2.r 4) R = 4r
35. A heater boils a certain quantity of water in time t1. Another heater boils the same quantity of water in time t2. If both the heaters are connected in series, the combination will boil the same quantity of water in time .. 
36. A piece of copper and another of germanium are cooled from room temperature to 40K. Then the resistance of ....
1) each of then decreases 2) each of them increases
3) copper increases and germanium decreases
4) copper decreases and germanium increases
37. A bar magnet of pole strength m and magnetic moment M is divided into two equal pieces by cutting it perpendicular to its length. Then ..
1) m is halved and M is doubled 2) both m and M are halved
3) m is halved but M remains the same 4) m remains the same but M is halved
38. A magnetized wire of magnetic moment M is bent into are arc of a circle that subtends an angle of 60° at the centre. Then the equivalent magnetic moment is .. 
Answers: 1-2, 2-2, 3-4, 4-3, 5-4, 6-4, 7-1, 8-1, 9-3, 10-2, 11-3, 12-2, 13-1, 14-3, 15-3, 16-2, 17-2, 18-4, 19-3, 20-1, 21-1, 22-1, 23-3, 24-1, 25-2, 26-2, 27-2, 28-4, 29-4, 30-2, 31-4, 32-3, 33-2, 34-1, 35-1, 36-4, 37-4, 38-3.
