Question

A small sphere that carries a charge q is whirled in a circle at the end of an insulating string. The angular frequency of rotation is ω. What average current does this rotating charge represent? (Use any variable or symbol stated above as necessary.)

Answer 1

i = qω/2π

Step-by-step explanation:

Since the charge moves in a circle, its velocity v = rω. where r is the radius of the circle and ω the angular frequency of the charge.

The distance it covers in one cycle is the circle's circumference,d = 2πr.

The time it takes to cover this distance, t = d/v = 2πr/rω = 2π/ω

We know that current i = charge/time = q/t = q/2π/ω = qω/2π

So, the average current, i = qω/2π