Practice portal › Electromagnetic Induction › Self-Inductance

What is the self-inductance of a coil which produces a self-induced emf of 5 V when the current changes from 3 A to 2 A in one millisecond?

Asked in GUJCET 2007 · Self-inductance and self-induced EMF

Answer: (1) 5 mH

Step-by-step solution

Given: ε = 5 V; the current changes from 3 A to 2 A, so |Δ I| = 1 A; Δ t = 1 ms = 10⁻³ s.

Idea: ε = L (|Δ I|)/(Δ t), so L = (ε Δ t)/(|Δ I|).

L = (5 × 10⁻³)/1 = 5×10⁻³ H.

So the self-inductance is 5 mH.

Why the other options are wrong

More Self-Inductance questionsAll Self-Inductance questions →

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

Practise this with a timer