WE KNOW THAT LIKE POLES REPULCE ,UNLIKE

POLES ATTRACT BUT IN CASE OF EARTH AND MAGNETIC COMPASS,’‘HOW DO NORTH POLE OF MAGNETIC COMPASS ATTRACT TO NORTH POLE OF EARTH’‘?DOES IT SEEMS TO BE CONTRIDICT EACH OTHER?

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.