Question

Work done in carrying a 2 coulomb charge in a circular orbit of ra dius 3 m around a charge of 10 coulomb is

Answer 1

Q = charge at the center = 10 C

r = radius of circular orbit = 3 m

electric potential at all points on the circumference of the circular orbit is given as

V = kQ/r

inserting the values

V = (9 x 10⁹) (10)/3

V = 3 x 10¹⁰ Volts

2 C moves on the circumference of the circular orbit. that means charge 2C moves on equipotential surface since electric potential is same at all points on the circumference of orbit. for an equipotential surface , we know that

ΔV = potential difference = 0

q = charge being moved = 2 C

hence work done is given as

W = q ΔV

W = 2 x 0

W = 0 J