Question

In a transformer, the coefficient of mutual inductance between the primary and the secondary coil is 0.2 henry. When the current changes by 5 ampere/second in the primary, the induced e.m.f. in the secondary will be

• A. 5 V
• B. 1 V
• C. 25 V
• D. 10 V

Answer 1

Answer: (B)

1 V

Answer 2

$e = M\frac{di}{dt} = 0.2 \times 5 = 1\mspace{6mu} V$