Presentation on the Electromagnetism induction PRESENTED BY AYESHA-YASIN ROLL NO :31 BS-IT 3 RD SEMESTER

Electromagnetism induction: The current produces in the conductor due to its motion in the magnetic field is called induced current Induced EMF If we change the resistance of the conductor by adding different resistors in the loop and move it in the magnetic field with the same speed every time, we find that the product of the induced current I and resistance R of the loop remains constant such that I x R=constant This constant is called induced emf

This phenomena of production of the induced current and induced emf is called electromagnetic induction

Different Methods Of producing induced EMF There are many methods of producing induced emf by changing magnetic flux through it.Some of them is given below Bar magnet and a coil By changing area of coil or loop

Bar Magnet and a coil of a wire:

When a magnet moves toward a loop of wire, the ammeter shows the presence of a current (a) When the magnet is held stationary, there is no current (b) When the magnet moves away from the loop, the ammeter shows a current in the opposite direction (c) If the loop is moved instead of the magnet, a current is also detected

Electromagnetism due to the changing of the area of coil

The current can be induced in a coil by changing the area of a coil in a constant magnetic field. No current is induced in the coil of constant area that is placed in constant magnetic field When the area of the coil is reduced in the magnetic field then induced emf is produced so current is appears as shown in figure The current disappears when there will be no change of area

If the coil is distorted coil is brought to its original circular shape by increasing the area,an opposite current is induced which lasts as long as the area is changing.When we stop changing the area of coil, then the galvanometer show deflection means no current produced