Question

The magnetic field at a point x on the axis of a small bar magnet is equal to the at a point y on the equator of the same magnet. The ratio of the distances of x and y from the centre of the magnet is 

(a) 2^–3 

(b) 2^–(1/3) 

(c) 2³ 

(d) 2^+(1/3)

Answer 1

The correct option (d) 2^+1/3

Explanation:

On the axis, B₁ = (2M/x³)

On the equator, B₂ = (M/y³)

as B₁ = B₂

(2M/x³) = (M/y³)

∴ (x/y)³ = 2

(x/y) = 2^(1/3)