Question

A coil of area \(3 \text{ m}^{2}\) is at right angles to a magnetic field of \(0.05 \text{ Wb/m}^{2}\). If the field is decreased to \(20%\) of its value in \(10 \text{ s}\) , the induced e.m.f. is.

• A. \(10 \text{ mV}\)
• B. \(12 \text{ mV}\)
• C. \(15 \text{ mV}\)
• D. \(20 \text{ mV}\)

Hint:

E.m.f is the rate of change of flux; flux is $B \times A$ when perpendicular.

Answer 1

The Correct Option is B