10 Question-answer on electric potential
1. Inside a hollow charged spherical conductor, the potential
(a) Is constant
(b) Varies directly as the distance from the centre
(c) Varies inversely as the distance from the centre
(d) Varies inversely as the square of the distance from the centre
Ans: (a)
2. Two copper spheres of same radii one hollow and other solid are charged to the same potential then:
(a) Both will hold same charge
(b) solid will hold more charge
(c) hollow will hold more charge
(d) Hollow cannot be charged.
Ans: ( a)
3. A particle A has charge +q & particle B has charge +4q with each of them having the same mass m. when allowed to fall from rest through the same electrical potential difference, the ratio of their speeds VA/VB will become:
(a) 2 : 1
(b) 1 : 2
(c) 1 : 4
(d) 4 : 1
Ans: (b)
4. 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
Ans: (b)
5. The electric potential at the surface of an atomic nucleus (Z = 50) of radius of 9 × 10-15m is:
(a) 80 V
(b) 8 × 106 V
(c) 9 V
(d) 9 × 105 V
Ans: (b)
6. A cube of a metal is given a positive charge Q. Far the system, which of the following statement 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
Ans: ( c)
7. A hollow metallic sphere of radius 10 cm is charged such that potential of its surface is 80 volt. The potential at the centre of the sphere would be:
(a) Zero
(b) 8 V
(c) 80 V
(d) 800 V
Ans: ( c)
8. An electric cell does 5 J of work in carrying 10 C charge around close circuit. The electromotive force of the cell is:
(a) 2 V
(b) 0.5 V
(c) 4 V
(d) 1 V
Ans:
Ans: (b)
9. Potential of two equal negative point charges 2ยต C each held 1 m apart in air is:
(a) 2 J
(b) 2e V
(c) 4 J
(d) 0.036 J.
Ans: ( d)
10. Which of the following is /are proportional to the inverse square of the distance x?
(a) The potential at a distance x from an isolated point charge
(b) The electric field at a distance x from an isolated point charge
(c) The force per unit length between two thin, straight, infinitely long current carrying conductors, parallel to each other, separated by a distance x
(d) The gravitational attraction between two small bodies kept at a distance x apart.
Ans: (b)