Question

A long straight current carrying wire normally passes through the center of circular loop if the current through the wire increase, will there be an induced emf in the loop ?

Answer 1

As, induced e.m.f directly proportional to rate of change of magnetic flux $\left({\varphi }_8\right)$

${\varphi }_B=B\cdot A=BA\cos \theta$

$B\perp A\Rightarrow {\varphi }_B=BA\cos {90}^{\circ }=0$

So, induced emf $=0$

No, there will not be an induced emf occur in the loop as magnetic flux doesn't change linked with the circular loop because magnetic field lines are parallel to the plane of the loop.