State an important advantage of ac over dc.

A portable radio has a built in transformer so that if can work from the mains instead of batteries. Is this a step up or step down transformer?

Two coils A and B of insulated wire are kept close to each other. Coil A is connected to a galvanometer. While coil B is connected to a battery through a key. What would happen if
(i) a current is passed through coil B by plugging the key?
(ii) the current is stopped by removing the plug from the key?

State Faraday’s laws of electromagnetic induction.

Can two magnetic lines of force intersect? Justify your answer.

Give some uses of electromagnets