Question

Calculate the value of emf in an inductor if the value of inductance is 15H and an average current of 5A flows through it in 10s.

(a) 15V

(b) 7.5V

(c) 10V

(d) 5.5V

The question was asked in an interview for job.

Query is from Energy Stored in an Inductor topic in portion Inductance in a DC Circuit of Basic Electrical Engineering

Answer 1

Right choice is (b) 7.5V

To explain I would say: The expression for emf in an inductive circuit is:

emf = LdI/dt

Substituting the values from the given question, we get emf = 7.5V.