Question

A non conducting ring carries linear charge density λ. It is rotating with angular speed ω about its axis. The magnetic field at its centre is

(A) 3μ0λω/2π

(B) μ0λω/2

(C) μ0λω/π

(D) μ0λω

Answer 1

Correct option (B) μ0λω/2

Explanation:

The linear charge density is λ.

The magnetic field at the centre of ring is given by

Now, the current is charge per unit time