What is meant by inductance?

• A. Ability to produce heat when current flows
• B. Ability to store electrical energy in electromagnetic fields
• C. The rate at which current changes
• D. The total resistance to current

Answer: (B)

Inductance is the property of an inductor that causes it to oppose changes in current by storing energy in its magnetic field. When current changes, an emf is induced proportional to the rate of change of current, described by V = L di/dt. The energy stored in the magnetic field of the inductor is (1/2) L I^2. This combination—opposing current change and storing energy magnetically—is what inductance is all about.

The other ideas describe related but separate concepts: heating from resistance, which is not inductance; the rate of current change itself, which is what V = L di/dt uses but isn’t the definition; and total resistance, which is a different property altogether.