Whenever there is a relative motion between the magnet and the solenoid, there is a flow of electricity. This phenomenon is known as electromagnetic induction. The current thus induced is the induced current. The voltage induced is the induced emf.
Whenever there is a change in the magnetic flux linked with a coil, an emf is induced in the coil. This phenomenon is known as electromagnetic induction.
Factors affecting the induced current
- Number of turns of the coiled conductor
- Strength of the magnet
- Speed of the movement of the magnet or the
solenoid
Induced emf would be maximum if the conductor is moved perpendicular to the magnetic field lines.
Fleming’s right hand rule
Imagine a conductor moving perpendicular to a magnetic field. Stretch the forefinger, middle finger and the thumb of the right hand in mutually perpendicular directions. If the forefinger represents the direction of the magnetic field, and the thumb represents the direction of the motion of the conductor, then, the middle finger represents the direction of induced current.
Alternating Current (AC)
A current that changes direction at
regular intervals of time, is an alternating current.
Direct Current (DC)
A current that flows only in one direction continuously is a direct current.
Generator
Generator is a device that converts mechanical energy into electrical energy by making use of electromagnetic induction.
AC Generator
Parts of AC generator
Field Magnet
The magnet that creates magnetic flux in the generator
Armature
An arrangement of insulated conducting wire wound on a soft iron core. This can be made to rotate about an axis.
Slip Rings
Metal rings which are welded together with the armature coil. They rotate along with the armature on the same axis of rotation as the armature
Brushes
They are arrangements which always make contact with the slip rings. Current flows through them to external circuits
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