question_answer 44)

  A bar magnet of magnetic moment M and moment of inertia(about centre, perpendicular to length) is cut into two equal pieces, perpendicular to length. Let T be the period of oscillations of the original magnet about an axis through the mid point, perpendicular to length, in a magnetic field . What would be the similar period for each piece ?

Answer:

                  The moment of inertia of a bar magnet of mass m, lengthabout an axis passing through its centre and perpendicular to its length is . Let M be the magnetic moment of the magnet, B is the uniform magnetic field in which the magnet is oscillating, then time period of oscillation is                                                      ?.. When magnet is cut into two equal pieces, perpendicular to length, then moment of inertia of each piece of magnet about an axis perpendicular to length passing through its centre is Magnetic dipole moment, = Its time period of oscillation is