Question

The maximum current in the inductor IL(t)=Io(1 – e^-t/α) is __________

(a) Io e^-t/α

(b) Io

(c) 2Io

(d) -Io

This question was posed to me in an interview for job.

Question is taken from Dynamic Braking of DC Shunt Motors in portion Braking of DC Motors & Induction Motors of Electric Drives

Answer 1

Correct option is (b) Io

To explain: The IL(t)=Io(1 – e^-t/α)  is Io is the transient equation of the inductor current. At the steady state (t=∞) IL(t)=Io(1- e-∞) is Io. The maximum current in the inductor is Io.