Question

A loop $PQRS$ is moving $\theta$ in a magnetic field with uniform speed as shown in figure, then comment regarding the induced emf (e).

• A. $e_{RS}=1$
  
• B. $e_{PS}+e_{QP}=e_{RS}$
• C. $e_{QR}<e_{QP}$
• D. $e_{PS}+e_{QP}=e_{QR}$ and $e_{PQRSP}=0$
  

Answer 1

The correct option is D $e_{PS}+e_{QP}=e_{QR}$ and $e_{PQRSP}=0$


$e_{RS}=0$ since the length is along the velocity of the rod.
$e_{PS}+e_{QP}=e_{QS}$ but not $e_{RS}$
$e_{QR}>e_{QP}$
Since $e_{RS}=0$, $e_{PS}+e_{QP}=e_{QR}$
The flux in the entire loop is constant, so the induced EMF is zero.