Production of Induced E.M.F. and Current

Fig "a" is shown an insulated coil whose terminals are connected to a sensitive galvanometer G. It is placed close to a stationary bar magnet initially at position AB (shown dotted). As seen, some flux from the N-pole of the magnet is linked with or threads through the coil but, as yet, there is no deflection of the galvanometer. 

Now, suppose that the magnet is suddenly brought closer to the coil in position CD (see figure). Then, it is found that there is a jerk or a sudden but momentary deflection in the galvanometer and that this lasts so long as the magnet is in motion relative to the coil, not otherwise. The deflection is reduced to zero when the magnet becomes again stationary at its new position CD. It should be noted that due to the approach of the magnet, flux linked with the coil is increased. Next, the magnetic suddenly withdrawn away from the coil as in Fig "b" It is found that again there is a momentary deflection in the galvanometer and it persists so long 

induced in AB. The magnitude of this induced e.m.f. (and hence the amount of deflection in the galvanometer) depends on the quickness of the movement of AB From this experiment we conclude that whenever a conductor cuts or shears the magnetic flux. an em.f. is always induced in it. It is also found that if the conductor is moved parallel to the direction of the flux so that it does not cut it, then no end is induced in it.