Question

In an atom, an electron moves in an orbit of radius r with a speed v, the equivalent current is ?(a) ev/2πr(b) ev/2r(c) ev/2π(d) e/2πr​

Answer 1

current = charge per unit time

i = e/T

T = 2πr/v

i = ev/2πr (a)

Answer 2

Given:

The radius of orbit = r

Speed of atom = v

Find:

Equivalent current in terms of r, v, e

Solution:

We know that,

I = Q / t where  I is equivalent current, Q is charge of electron and t is time

v = 2*π*r/t

t =  2*π*r / v

Q = e for electron

I = e / (2*π*r / v)

I = e v / 2πr

Hence the answer is option (a)  ev/2πr