A charge q is uniformly distributed over the volume of uniform ball of mass m and radius r which rotates with angular velocity w about an axis passing through the centre. find magnetic moment.

Four long co-axial thin walled cylindrical conductor A, B, C and D have radii R. 2R 3R and 4R respectively. A and C carry current I and 31 respectively to plane of paper on the other hand, B and D carry and 41 respectively outward to plane of paper. Then 21

I need solution of these questions.............................Magnetic effect of current

A freely suspended iron rod does not point at N-S directions alwalys .why

 

 

What is magnetic entropy change? For my knowledge, I know entropy is randomness or disorder. So here that magnetic refers to the magnetic dipole moments?

Derive the relation between magnetic field intensity (H) and magnetization (M) for a magnetic material placed in a magnetizing field.