The figure shows an isosceles triangle wire frame with an apex angle equal to $\pi / 2$. The frame starts entering into the region of a uniform magnetic field $B$ with a constant velocity $v$ at $t = 0$. The longest side of the frame is perpendicular to the direction of velocity. If $i$ is the instantaneous current through the frame,then choose the alternative showing the correct variation of $i$ with time.

$A$ coil of cross-sectional area $A$ having $n$ turns is placed in a uniform magnetic field $B.$ When it is rotated with an angular velocity $\omega,$ the maximum $e.m.f.$ induced in the coil will be

$A$ rectangular wire loop of sides $8 \text{ cm}$ and $3 \text{ cm}$ with a small cut is moving out of a region of uniform magnetic field of magnitude $0.3 \text{ T}$ directed normal to the plane of the loop. The emf developed across the cut, if the velocity of the loop is $2 \text{ cm s}^{-1}$ in a direction normal to the shorter side of the loop, will be:

$XPQY$ is a vertical smooth long loop having a total resistance $R$, where $PX$ is parallel to $QY$ and the separation between them is $l$. $A$ constant magnetic field $B$ perpendicular to the plane of the loop exists in the entire space. $A$ rod $CD$ of length $L$ $(L > l)$ and mass $m$ is made to slide down from rest under gravity as shown in the figure. The terminal speed acquired by the rod is . . . . . . $m/s$. ($g$ = acceleration due to gravity)

$A$ $20\,cm$ long metallic rod is rotated with $210\,rpm$ about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. $A$ constant and uniform magnetic field of $0.2\,T$ parallel to the axis exists everywhere. The emf developed between the centre and the ring is $.......\,mV$. Take $\pi=\frac{22}{7}$.

$A$ conducting rod of length $l$ moves with a constant velocity $\upsilon$ perpendicular to a long,straight wire carrying a current $I$,as shown in the figure. Calculate the $emf$ generated between the ends of the rod.