$(i)$ $A$ compass needle gets deflected when brought near a current-carrying conductor. Why?
$(ii)$ What happens to the deflection of the needle when the current in the conductor is increased?

In domestic electrical wiring,which color of insulation is typically used for the neutral wire?

Which of the following appliances cannot be connected in a $15\, A$ current line?

Two coils $C_{1}$ and $C_{2}$ are wrapped around a non-conducting cylinder. Coil $C_{1}$ is connected to a battery and a key $K$,and coil $C_{2}$ is connected to a galvanometer $G$. On pressing the key $K$,current starts flowing in the coil $C_{1}$. State your observations in the galvanometer for the following cases:
$(i)$ When key $K$ is pressed on.
$(ii)$ When current in the coil $C_{1}$ is switched off.
$(iii)$ When the current is passed continuously through coil $C_{1}$.
$(iv)$ Name and state the phenomenon responsible for the above observation. Write the name of the rule that is used to determine the direction of the induced current.

To find the direction of the magnetic field around a current-carrying conductor,we use Fleming's left-hand rule.

What is the frequency of $220 \ V$ $DC$ voltage? (In $Hz$)