(i) When key is pressed on, the galvanometer needle deflects momentarily in one direction.
(ii) When the current in the coil C1 is switched off, the galvanometer needle deflects again
momentarily but in opposite direction to that in the previous case.
(iii) When current is passed continuously through coil C1, no deflection is observed in the galvanometer.
(iv) The phenomenon responsible for the above observations is electromagnetic induction.
Electromagnetic Induction: The process, by which a changing magnetic field in a conductor induces a current in another conductor placed nearby, is called electromagnetic induction.
• Fleming’s right hand rule is used to determine the direction of current produced in the phenomena of electroynagnetic induction.