The device used for producing electric current is called a

The essential difference between an $AC$ generator and a $DC$ generator is that

Two circular coils $A$ and $B$ are placed close to each other. If the current in the coil $A$ is changed,will some current be induced in the coil $B$? Give reason.

In the activity,how do we think the displacement of rod $AB$ will be affected if:
$(i)$ current in rod $AB$ is increased;
$(ii)$ a stronger horse-shoe magnet is used; and
$(iii)$ length of the rod $AB$ is increased?

What is the role of the split ring in an electric motor?

List the properties of magnetic field lines.