A) 5 H
B) 3 H
C) 4 H
D) 2 H
Correct Answer: A
Solution :
Key Idea: emf induced in the circuit is directly proportional to the rate of change of current. emf induced \[\propto \]rate of change of current i.e., \[e\propto \frac{di}{dt}\] when the proportionality constant is removed, the some constant L comes here. Hence, \[e=-L\frac{di}{dt}\] ?(i) Given, \[e=0.4\,V,\] \[\frac{di}{dt}=\frac{0.2-1}{10}=-\frac{0.8}{10}=-0.08A/s\] \[\therefore \] \[0.4=-L(-0.08)\] or \[L=\frac{0.4}{0.08}=5H\] Note: The minus sign in Eq. (i) is a reflection of Lenzs law.You need to login to perform this action.
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