Q.1. In a region of constant potential
(a) the electric field is uniform
(b) the electric field is zero
(c) the electric field shall necessarily change if a charge is placed outside the region
(d) None of these
Answer
Answer: (b)Q.2. A cube of a metal is given a positive charge Q. For this system, which of the following statements is true?
(a) Electric potential at the surface of the cube is zero
(b) Electric potential within the cube is zero
(c) Electric field is normal to the surface of the cube
(d) Electric field varies within the cube
Answer
Answer: (d) Surface of metallic cube is an equipotential surface. Therefore, electric field is normal to the surface of the cube.Q.3. The electric potential inside a conducting sphere
(a) increases from centre to surface
(b) decreases from centre to surface
(c) remains constant from centre to surface
(d) is zero at every point inside
Answer
Answer: (c)Q.4. It becomes possible to define potential at a point in an electric field because electric field
(a) is a conservative field
(b) is a non-conservative field
(c) is a vector field
(d) obeys principle of superposition
Answer
Answer: (a)Q.5. An equipotential surface is that surface
(a) on which each and every point has the same potential
(b) which has negative potential
(c) which has positive potential
(d) which has zero potential
Answer
Answer: (a)Q.6. If a unit positive charge is taken from one point to another over an equipotential surface, then
(a) work is done on the charge
(b) work is done by the charge
(c) work done is constant
(d) no work is done
Answer
Answer: (d) On the equipotential surface, electric field is normal to the charged surface (where potential exists) so that no work will be done.Q.7. The positive terminal of 12 V battery is connected to the ground. Then the negative terminal will be at
(a) – 6 V
(b) + 12 V
(c) zero
(d) – 12 V
Answer
Answer: (d) When negative terminal is grounded, positive terminal of battery is at +12 V. When positive terminal is grounded, the negative terminal will be at –12 V.Q.8. The electric potential at a point on the equatorial line of an electric dipole is
(a) directly proportional to distance
(b) inversely proportional to distance
(c) inversely proportional to square of the distance
(d) None of these
Answer
Answer: (d)Q.9. A hollow metal sphere of radius 5 cm is charged such that the potential on its surface is 10 V. The potential at a distance of 2 cm from the centre of the sphere is
(a) zero
(b) 10 V
(c) 4 V
(d) 10/3 V
Answer
Answer: (b) Potential at any point inside the sphere = potential at the surface of the sphere = 10VQ.10. Figure shows two hollow charged conductors A and B having same positive surface charge densities. B is placed inside A and does not touches it. On connecting them with a conductor
(a) charge will flow from A to B
(b) charge will flow from B to A
(c) charge oscillates between A and B
(d) No charge will flow.