Q. Flux $\phi$ (in weber) in a closed circuit of resistance 20$\Omega$ varies with time t (in second) according to equation$\ \phi = 6t^{2} - 5t + 1.$ The magnitude of the induced current at t =0.25 s is
A) 1.2 A
B) 0.8 A
C) 0.6 A
D) 0.1 A
Explanation
(d) From, Faraday’s second law,$e = - \frac{d\phi}{db}$
= $- \lbrack 12t - 5\rbrack$
= $- \left\lbrack 12 \times (0.25) - 5 \right\rbrack = + 2$
Now, $\ i = \frac{e}{R} = \frac{2}{20} = 0.1\ A$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.