Q1 Obtain an expression for the torque acting on a bar magnet placed in a uniform magnetic field and define magnetic moment. Write also its unit. Solution

Q2 Determine the expression for the magnetic field due to a short bar-magnet (magnetic dipole) at a point on the (i) axis.
(ii) equatorial line of the dipole. Solution

Q3 What are the elements of earth's magnetic field? Show them in a labelled diagram. What is their importance? Write relations among them. How does the value of dip vary from equator to pole? Solution

Q4 What are magnetic lines of force? Give their properties and trace them for a bar-magnet. Solution