Manipal MET2014PhysicsMagnetic Effects of Current
A short bar magnet is placed with its south pole towards geographical north. The neutral points are situated at a distance of 20 cm from the centre of the magnet. If B_H=0.3 10⁻⁴ ~Wb / m ^2 then the magnetic moment of the magnet is
Options
- A9000ab - amp cm ^2
- B900 ab - amp cm ^2
- C1200ab - amp cm ^2
- D225 a b-a m p cm ^2
Correct answer
C. 1200ab - amp cm ^2
Step-by-step solution
At neutral point magnetic field due to magnet = Horizontal component of the earth's magnetic field. aligned & ₀ 4 2 M r^3 =B_H 10⁻⁷ 2 M 1 (0.2)^3 =0.3 15^4 & M=1.2 amp m ^2=1200 ab - amp cm ^2 aligned