Question

What should be the value of self inductance of an indicator that should be connected to $220$V, $50$Hz supply so that a maximum current of $0.9$A flows through it?

• A. $11$H
• B. $2$H
• C. $1.1$H
• D. $5$H

Answer 1

The correct option is D $5$H

The emf across the inductor is given by:

$|e|=\frac{Ldi}{dt}$

$220=L\times \frac{0.9}{1/50}$

$L=4.88=5$H.