Electromagnetic Induction — Important Questions

They oppose the decrease of flux, They are also called Foucault currents, Their magnitude depends on the resistance of the metal

Eddy currents are induced currents in the body of the metal. They oppose the change in flux, are also called Foucault currents, and become feeble when resistance is large.

Self-induction is an emf induced in the same coil due to change of its own current, Mutual induction is an emf induced in a secondary coil due to change of current in a primary coil, Both are measured in henry

Self-induction and mutual induction are distinct. The coefficient of self-induction and mutual inductance both use the unit henry.

L is proportional to N squared, L is proportional to cross-sectional area A, L becomes larger with an iron core of relative permeability greater than 1

For a solenoid, L = μ0N^2A/l and with a core L = μrμ0N^2A/l. So L rises with N^2, A, and μr.

0 V

No potential difference is induced when either the velocity or the length is parallel to the magnetic field. Since the conductor moves parallel to the field, the motional emf is zero.