If field lines of a magnetic field are crossed at a point,what does it indicate?

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 $DC$.

The magnetic field produced by a current-carrying solenoid depends directly upon the strength of the current.

$A$ circular loop placed in a plane perpendicular to the plane of paper carries a current when the key is $ON$. The current as seen from points $A$ and $B$ (in the plane of paper and on the axis of the coil) is anti-clockwise and clockwise respectively. The magnetic field lines point from $B$ to $A$. The $N-$ pole of the resultant magnet is on the face close to

$A$ device used for producing current is:

Draw a diagram to represent a uniform magnetic field in a given region.