Question

The magnetic flux through a coil is $4 \times 10^{-4} \text{ Wb}$ at time $t = 0$. It reduces to $30%$ of its original value in time $t$ second. If e.m.f. induced in the coil is $0.56 \text{ mV}$ then the value of $t$ is

• A. 0.5 s
• B. 0.4 s
• C. 0.8 s
• D. 0.7 s

Hint:

Faraday's Law: Emf is the rate of change of magnetic flux.

Answer 1

The Correct Option is A