Practice portal › Electromagnetic Induction › Self-Inductance

A current I passes through an inductor of self-inductance L=4 H. If the current is doubled, what will be the new self-inductance of the inductor?

Asked in GSEB Board March 2023 · Self-inductance and self-induced EMF

• (1) 4 H
• (2) 2 H
• (3) zero
• (4) 8 H

Step-by-step solution

Why the other options are wrong

• (2) Reads L=(NΦ)/I as if the flux stayed fixed while I doubled. The flux is produced by the current, so it doubles too and the ratio stays 4 H.
• (3) Inductance does not vanish when the current changes size or is steady. It is a property of the coil, fixed by its turns, area, length and core.
• (4) Treats inductance as proportional to the current. Doubling I doubles the flux linkage, not L; it is the stored energy 1/2LI² that changes, by a factor of 4.

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.