$A$ device used for producing current is:

How will the magnetic field produced in a current-carrying circular coil change if we increase the:
$(i)$ value of current flowing through it?
$(ii)$ distance of point $P$ from the coil?
$(iii)$ number of turns of the coil?

Answer the following questions:
$(i)$ What is the direction of magnetic field lines outside a bar-magnet?
$(ii)$ Why two magnetic field lines cannot intersect each other?
$(iii)$ What is indicated by crowding of magnetic field lines in a given region?
$(iv)$ What is the frequency of $AC$ in India?
$(v)$ State one advantage of $AC$ over $DC$.

State the observation made by Oersted on the basis of his experiment with current carrying conductors.

State the rule to determine the direction of magnetic field produced around a current-carrying conductor.

The strength of the induced potential difference depends on the relative speed between the coil and the magnet.