Question

Magnetic flux through loop is $\varphi$$=t^2-5t+6$,
emf in loop will zero at time____ (sec)?

• A. 2
• B. 3
• C. 2.5
• D. 6

Answer 1

The correct option is C 2.5

$e=\frac{d}{dt}\left({\varphi }_B\right)=\frac{d}{dt}(t^2-5t+6)$
$=2t-5$
at t = 2.5 sec, ($e=0$)