Question

A coil of insulated copper wire is connected to a galvanometer. What would be seen if a barmagnet with its north pole towards one face of the coil is

(i) moved quickly towards it(ii) moved quickly away from it(iii) placed near its one face and name the phenomena involved in it.

Answer 1

(i) Here the magnetic flux linked with the coil will increase. Due to this, an induced current flows in the coil and galvanometer shows momentary deflection.
(ii) In this case,the magnetic flux linked with the coil changes. Due to this an induced current flows in the coil but in a direction opposite to that in above case.
(iii) Here the magnet is held stationary. There will be a magnetic flux in the coil. But it remains constant since the magnetic flux does not change. As a result there is no induced current in the coil and galvanometers shows no deflection.
Name of the phenomena involved= Electromagnetic induction