Question
Explain the concept of self induction.
✓
Answer
Consider an isolated coil or circuit in which there is a current I. The current produces a magnetic flux linked with the coil.
The magnetic flux linked with the coil can be changed by varying the current in the coil itself, e.g., by breaking and closing the circuit. This produces a self-induced emf in the coil, called a back emf because it opposes the change producing it. It sets up an induced current in the coil itself in the same direction as the original current opposing its decrease when the key $K$ is suddenly opened. When the key $K$ is closed, the induced current is opposite to the conventional current, opposing its increase.
When the current through a coil changes continuously, e.g., by a time-varying applied emf, the magnetic flux linked with the coil also goes on changing.
The production of induced emf in a coil, due to the changes of current in the same coil, is called self induction.
The magnetic flux linked with the coil can be changed by varying the current in the coil itself, e.g., by breaking and closing the circuit. This produces a self-induced emf in the coil, called a back emf because it opposes the change producing it. It sets up an induced current in the coil itself in the same direction as the original current opposing its decrease when the key $K$ is suddenly opened. When the key $K$ is closed, the induced current is opposite to the conventional current, opposing its increase.
When the current through a coil changes continuously, e.g., by a time-varying applied emf, the magnetic flux linked with the coil also goes on changing.
The production of induced emf in a coil, due to the changes of current in the same coil, is called self induction.
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