Question

A short bar magnet is kept at a distance of 30 cm from the centre of the compass box on D.M, which is in Tan A position. The deflection is 45${}^0$. If the horizontal component of earth's field strength is 30 A/m, the magnetic moment of the magnet is

• A. $0.128\pi A{m}^2$
• B. $1.28\pi A{m}^2$
• C. $128\pi A{m}^2$
• D. $12.8\pi A{m}^2$

Answer 1

The correct option is D $12.8\pi A{m}^2$