Question

The arm $PQ$ of a rectangular conductor is moving from $x$ $=0$ to $x=2b$ outwards and then inwards from $x=2b$ to $x$ $=0$ as shown in the figure. $A$ uniform magnetic field perpendicular to the plane is acting from $x=0$ to $x=b$. Identify the graph showing the variation of different quantities with distance:

• A. (A)-Flux, (B)-Power dissipated, (C)-EMF
• B. (A)-Power dissipated, (B)-Flux, (C)-EMF
• C. (A)-Flux, (B)-EMF, (C)-Power dissipated
• D. (A)-EMF, (B)-Power dissipated, (C)-Flux

Answer 1

Answer: (C)

As rod moves in field area increases upto $x=b$
then field is absent and again flux is generated on return journey from $x=b$ to $x=0$.
Thus plot $A$ for flux.
$\Rightarrow e=-\frac{d\varphi }{dt}$
$\Rightarrow$ curve $B$ for emf
$\Rightarrow$ Power dissipated $=vi$
$\Rightarrow$ curve $C$ for power dissipated