The branch of science that covers the comprehensive study of electricity and magnetism is known as $.........$.

The diagram below shows a coil connected to a centre zero galvanometer $G$. The galvanometer shows a deflection to the right when the $N$ pole of a powerful magnet is moved to the right as shown.
$(i)$ Explain why the deflection occurs in the galvanometer.
$(ii)$ Does the direction of current in the coil appear clockwise or anticlockwise when viewed from end $A$?
$(iii)$ State the observation in $G$ when the coil is moved away from $N$.
$(iv)$ State the observation in $G$ when,both coil and the magnet,are moved to the right at the same speed.

An alternating electric current has a frequency of $50 \ Hz$. How many times does it change its direction in one second (in $\times$)?

An electric generator works on the principle of electromagnetic induction.

$(a)$ Which effect of the electric current is utilised in the working of an electrical fuse?
$(b)$ Is a fuse connected in series or in parallel in a household circuit?
$(c)$ Draw a schematic labelled diagram of a domestic circuit which has a provision of a main fuse,meter,one light bulb,and a switch socket.

Name four appliances wherein an electric motor,a rotating device that converts electrical energy to mechanical energy,is used as an important component. In what respect are motors different from generators?