State two ways by which the strength of an electromagnet can be increased.

List three sources of magnetic fields.

In an electric motor,a loop with many turns is arranged on an axis. What is it called?

The induced potential difference produced in a coil when a magnet is inserted into it does not depend upon:

What does the divergence of magnetic field lines near the ends of a current-carrying straight solenoid indicate?

Why does a magnetic compass needle pointing North and South in the absence of a nearby magnet get deflected when a bar magnet or a current carrying loop is brought near it? Describe some salient features of magnetic lines of field concept.