State the principle of working of an A.C generator.

You are given following current $\left(I\right)$ - time $\left(t\right)$graphs.

(a) Name the type of current in each case.

(b) Identify one source for each of the currents.

A coil of insulated wire is connected to a galvanometer. What would be seen if a bar magnet with its south pole towards one face of the coil is:

(a) moved quickly towards it?

(b) moved quickly away from it?

(c) placed near its one face?

(d) name the phenomena involved.