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 $DC$.

(N/A) $(i)$ Outside a bar magnet,the direction of magnetic field lines is from the North pole to the South pole.
$(ii)$ Two magnetic field lines cannot intersect each other because if they did,it would mean that at the point of intersection,the compass needle would point towards two different directions simultaneously,which is physically impossible.
$(iii)$ The crowding of magnetic field lines in a given region indicates that the magnetic field is stronger in that region.
$(iv)$ The frequency of $AC$ in India is $50 \, Hz$.
$(v)$ One major advantage of $AC$ over $DC$ is that $AC$ can be transmitted over long distances without significant loss of electrical energy.