Question

An e.m.f. of 5 volt is produced by a self inductance, when the current changes at a steady rate from 3 A to 2 A in 1 millisecond. The value of self inductance is

• A. zero
• B. 5 H
• C. 5000 H
• D. 5 mH

Answer 1

The correct option is D 5 mH

we know that em.f develop by the inductor due to change in current

$E=-L\frac{dI}{dt}=-L\frac{(2-3)}{{10}^{-3}}=L\times {10}^3$

$\Rightarrow L\times {10}^3=5$

$\Rightarrow L=5mH$

Hence the correct option is D