Question

The average e.m.f. induced in a coil in which a current changes from 0 to 2 A in 0.05 s is 8 V. The self inductance of the coil is

• A. 0.1 H
• B. 0.2 H
• C. 0.4 H
• D. 0.8 H

Answer 1

Answer: (B)

0.2 H

Answer 2

$e = - L \left( \frac { d i } { d t } \right) \Rightarrow 8 = - L \times \left( - \frac { 2 } { 0.05 } \right)$