## Self Assessment Quiz

1. Two point charges, q each, are attached to the ends of a rigid rod of length . The rod is rotated with an angular speed  about an axis through the centre of the rod and perpendicular to it. Calculate the electric and the magnetic dipole moment  of the system taking the centre of the rod as the origin. What is the total power radiated by this system?

2. An electric dipole of strength  initially lies along the x-axis centred at origin. The dipole rotates in the x-y plane about the z-axis at an angular frequency  Calculate the radiation field and the radiated power as seen by an observer in the x-z plane at an angle  to the z-axis.

3. Neutron stars are a class of very dense stars consisting primarily of neutrons.  The neutron star rotates with an angular frequency  about an axis which makes an angle  with the direction of the magnetic moment.  Assume the radius of the star to be 10 km and the angular frequency of rotation to be 100 rad/s about the z-axis which makes angle of  with the magnetic moment vector of the neutron star.  Take the strength of the magnetic field at the magnetic equator to be T. Calculate the total power radiated.