The diagram in figure. shows a coil wound around a soft iron bar XY. (a) State the polarity at the end X and Y as the switch is pressed. (b) Suggest one way of increasing the strength of electromagnet so formed.

What is an electromagnet? Name two factors on which the strength of magnetic field of an electromagnet depends and state how does it depend on the factors stated by you.

A magnet kept at the centre of two coils A and B is moved to and fro as shown in the diagram. The two galvanometers show deflection.

State with a reason whether :

x > y

or

x < y [x and y are magnitudes of deflection]

Why does a current carrying freely suspended solenoid rest along a particular direction? State the direction in which it rests.