Through a conducting coil along its axis, a short bar magnet is rapidly pulled with uniform velocity with, with its north pole entering the coil first. Plot the variation of (i) flux, (ii) induced current and (iii) power dissipated in coil with time.

Explanation

Magnetic field due to magnet is given as
`B=(mu_(0))/(4pi).(2M)/(x^(3))`
`rArr" "Bprop(1)/(x^(3))rArrphiprop(1)/(x^(3))`
When a bar magnet is pulled rapidly through a conducting coil, then flux first increases, reaching to a maximum value and then decreases.

(ii) Induced current versus time t
When flux increases, then north pole is formed, current is anti-clockwise.
When flux decreases, then south pole is pormed, current is clockwise, (Taking anti-clockwise current as positive.)

(iii) As power `prop` induced current. The corresponding power versus t can be drawn as