Question

A steel wire of length 1 has a magnetic moment m it is then bent into a semicircular arc. The new magnetic moment is

Options

• m

• 2m/π

• m/π

• m × s

Answer 1

2m/π

Explanation:

m = m × 1 Where each pole's strength is insufficient.

When 1 = `pir + r = 1/pi`

Distance between poles = `2r = (2l)/pi`

M¹ = `m xx (21)/pi = (2m)/pi`