Explain the phenomenon of electromagnetic induction? Describe
an appropriate experiment to show that a current is set up in a
closed loop when an external magnetic field passing through the
loop increases or decreases.

Science - Exemplar Problems




Electromagnetic Induction: When a conductor is set to move inside a magnetic field or a magnetic field is set to be changing around a conductor, electric current is induced in the conductor. This is just opposite to the exertion of force by a current carrying conductor inside a magnetic field. In other words, when a conductor is brought in relative motion vis-à-vis a magnetic field, a potential difference is induced in it. This is known as electromagnetic induction. electromagnetic induction Activity: Demonstrating electromagnetic induction Materials Required: For this, take a galvanometer, coil, bar magnet and some wires. Procedure: The coil is inserted over a hollow tube of cardboard. With the help of wires, the two ends of the coil are attached to the galvanometer. The north pole of the bar magnet is moved towards the end ‘B’ of the coil. It is observed that the galvanometer needle shows deflection to right. When the magnet is moved away from the coil, the galvanometer needle shows deflection towards left. When the magnet is in static position, no deflection is seen in galvanometer needle. Induction of electric current in the coil is the cause of deflection in galvanometer needle. If the magnet is kept stationary and coil is moved; then also the galvanometer needle shows deflection. It can be concluded that when the coil and the bar magnet are in relative motion, a current is induced in the coil. Hope this helped u. Mark it as best answer......