Eddy currents are also known as Facault ’ s current .
Self-Induction
The phenomena of production of induced emf in a circuit due to change in current flowing in its own , is called self induction .
Coefficient of Self-Induction
The magnetic flux linked with a coil φ = LI where , L = = coefficient of self induction . The induced emf in the coil E = – L dl / dt
it unit of self induction is henry ( H ) and its dimensional formula is [ ML 2 T -2 A -
2 ]. Self – inductance of a long solenoid is given by normal text
L = μ o N 2 A / l = μ o n 2 Al where . N = total number of turns in the solenoid , 1 = length of the coil , n = number of turns in the coil and A = area of cross-section of the coil . If core of the solenoid is of any other magnetic material , then L = μ o μ r N 2 A / l Self – inductance of a toroid L = μ o N 2 A / 2πr Where , r = radius of the toroid Energy stored in an inductor E = 1 / 2 LI 2
Mutual Induction
The phenomena of production of induced emf in a circuit due to the change in magnetic flux in its neighbouring circuit , is called mutual induction .
Coefficient of Mutual Induction