Question

What is the energy stored in the magnetic field if the current in a coil has a constant inductance of L henrys grows at a uniform rate?

(a) LI/2

(b) LI^2/2

(c) L/2I

(d) L/2I^2

The question was posed to me in an interview.

My question comes from Energy Stored in an Inductor in chapter Inductance in a DC Circuit of Basic Electrical Engineering

Answer 1

Right choice is (b) LI^2/2

The explanation: EMF induced in the coil is Ldi/dt.

Energy=ei*dt=Lidi/dt*dt=Li^2/2.