A steady current of 2A flows in a coil of emf 12V for 0.4s. A back emf of 3V was induced during this period. The stored energy in the loop that can be utilized is
A
9.6J
B
2.4J
C
12.0J
D
7.2J
Verified Correct Answer: B.
Physical Principles & Numerical Solution
Energy stored = Ivt = current x back e.m.f x time
= 2 x 3 x 0.4
= 2.4J
Source: Myschool Past Questions Archive (Record #12800)