A magnet of magnetic moment 2 ~J ~T ⁻¹ is aligned in the direction of magnetic field of 0.1 ~T . What is the net work done to bring the magnet normal to the magnetic field?

Step-by-step solution

Given that, magnetic moment, M=2 JT ⁻¹ Magnetic field, B=0.1 ~T Since, magnetic moment is aligned in the direction of magnetic field, i.e. initial angle, ₁=0^ When magnet is normal, then final angle, ₂=90^ Using relation for work done, W=-M B ( ₂- ₁ ) Substituting the values, we get aligned W & =-2 0.1 ( 90^ - 0^ ) & =-2 0.1(0-1)=0.2 ~J aligned Hence, 0.2 ~J work will be done to rotate a magnet from 0^ to 90^ angle with in magnetic field.