Class X - SSLC - Physics Quick Notes : 3 - Electromagnetic induction

In AC generator the rotating part is armature.
$$\frac{V_{s}}{V_{p}} = \frac{N_{s}}{N_{p}} ,  \frac{V_{s}}{V_{p}}  = \frac{l_{p}}{l_{s}} $$
Electromagnetic induction
Whenever there is change in the magnetic flux linked with a coil, an cmf is induced in Ihe coil. This phenomenon is electro- magnetic induction.

Fleming's right hand rule
Imagine a conductor moving perpendiculor to a magnetic field. Stretch the fore fingure, middle finger and thump of the right hand mutually perpendicular directions. If the fore finger represents the direction of the magnetic field and thump respresents the direction of motion of the conductor, then, the middle finger represents the direction of the induced current. Fleming's right-hand rule (for generators) shows the direction of induced current when a conductor attached to a circuit moves in a magnetic field. It can be used to determine the direction of current in a generator's windings.

AC Current
Current that changes direction at regular intervals of time, is an alternating currenl(AC).Alternating current (AC) is an electric current which periodically reverses direction, in contrast to direct current (DC) which flows only in one direction.

DC Current
A current that flows only in one direction contiously is a direct current. Direct current is the one directional or unidirectional flow electric charge.

Mutual induction
Consider two coils of wire kept side by side. When the strength or direction of the current in one coil changes, the magnetic flux around it changes. As a result, an cmf is induced in the secondary coil. This phcnoncnon is the mutual induction. Mutual induction is defined as the property of the coils that enables it to oppose the changes in the current in another coil.

Self induction
The change in magnetic flux due to the flow of an AC in a solenoid will generate a back cmf in the same solenoid in a direction opposite to that applied to it. This phenoenon is known as the self induction. Induction of an electromotive force in a circuit by a varying current in the same circuit.

Inductor
Inductor arc coils used to oppose the changes in electric current in a ciruit. They are used to control current in a circuit to the desired value without loss of power