12th Unit Test Sankalp Objective
12th Unit Test Sankalp Objective
12th Unit Test Sankalp Objective
2. If I is the current through a wire and 'e' is the charge of electron then the number of electrons in t seconds
will be given by -
Ie
(A) (B) e/It
t
6. 1 Coulomb is equal to -
(A) 1 amp × 1 sec
(B) 1 amp / 1 sec
(C) 1 joule × 1 amp
(D) 1 joule / 1 sec
9. If a charged body attracts another body, the charge on the other body-
(A) must be negative
(B) must be positive
(C) must be zero
(D) may be negative or positive or zero
A R
D
R 2R R
B C
R
3
(A) R (B) 6R
2
2
(C) R (D) 3R
3
26 Rate of heat generated by electric current in a resistive circuit is expressed in-
(A) IR (B) IR2
(C) I2R (D) IR
29. The law, governing the force between electric charges is known as
(a) Ampere's law (b) Ohm's law
(c) Faraday's law (d) Coulomb's law
30. When the distance between the charged particles is halved, the force between them becomes
(a) One-fourth (b) Half
(c) Double (d) Four times
31. Inside a hollow charged spherical conductor, the potential
(a) Varies inversely as the square of the distance from the centre
(b) Varies directly as the distance from the centre
(c) Varies inversely as the distance from the centre
(d) Is constant
32. Two charged spheres of radii 10 cm and 15 cm are connected by a thin wire. No current will flow, if
they have
(a) The same charge on each
(b) The same field on their surfaces
(c) The same energy
(d) The same potential
33. The electric field inside a spherical shell of uniform surface charge density is
(a) Directly proportional to the distance from the centre
(b) Constant, less than zero
(c) Zero
(d) None of the above
34. Figure shows the electric lines of force emerging from a charged body. If the electric field at A and
B are EA and EB respectively and if the displacement between A and B is r then
A r B
EB
(a) EA (b) E A EB
r
EB
(c) E A EB (d) EA
r2
35 The figure shows some of the electric field lines corresponding to an electric field. The figure suggests
A B C
(a) E A E B EC (b) E A E B EC
(c) E A EC E B (d) E A EC E B
36. An electric dipole when placed in a uniform electric field E will have minimum potential energy, if the
positive direction of dipole moment makes the following angle with E
(a) (b) /2
37.A given charge is situated at a certain distance from an electric dipole in the end-on position experiences
a force F. If the distance of the charge is doubled, the force acting on the charge will be
(a) 2F (b) F / 8
(c) F / 4 (d) F / 2
38. The resistivity of a wire
(a) Increases with the length of the wire
(b) does not depend on length and area of cross-section of wire
(c) Decreases with the length and increases with the cross-section of wire
(d) None of the above statement is correct
39. On increasing the temperature of a conductor, its resistance increases because
(a) Mass of the electrons increases
(b) Relaxation time decreases
(c) Electron density decreases
(d) None of the above
40 If a charged body attracts another body, the charge on the other body :-
(A) must be negative (B) may be negative or positive or zero
(C) must be zero (D) must be positive
1
41 A man has five resistors each of value . What is the maximum resistance he can obtain by
5
connecting them ?
1 1
(A) 1 (B) 5 (C) (D)
2 5
42. Materials which allow larger currents to flow through them are called :-
(A) Conductors (B) Insulators (C) Semiconductors (D) Alloys
43. Conventionally, the direction of the current is taken as –
(A) the direction of flow to positive charge (B) the direction of flow of atoms
(C) the direction of flow of molecules (D) the direction of flow of negative charge
44. The unit of specific resistance is :-
(A) ohm- meter (B) mho (C) ohm (D) ohm per metre
45. Electric intensity is
(A) a vector quantity (B) a scalar quantity
(C) neither scalar nor vector (D) sometimes scalar and sometimes vector