$A$ metal rod $AB$ of length $50 \text{ cm}$ is moving at a velocity $8 \text{ ms}^{-1}$ in a magnetic field of $2 \text{ T}$. If the field is at $60^{\circ}$ with the plane of motion as shown in the figure,then the potentials $V_A$ and $V_B$ are related by

The figure shows four wire loops,with edge lengths of either $L$ or $2L$. All four loops move through a region of uniform magnetic field (directed out of the page) at the same constant velocity. Rank the four loops according to the maximum magnitude of the electromotive force (e.m.f.) induced as they move through the field,greatest first.

$A$ rectangular conducting loop of sides $8\, cm$ and $2\, cm$ with a small cut is moving out of a region of uniform magnetic field of magnitude $0.3\, T$ directed normal to the loop as shown in figures $(i)$ and $(ii)$. If the velocity of the loop is $1\, cm\, s^{-1}$,then the ratio of the voltage developed across $ab$ in case $(i)$ to case $(ii)$ is:

$A$ conducting rod $AB$ of length $l = 1\,m$ is moving with a velocity $v = 4\,m/s$. The velocity vector makes an angle of $30^o$ with the length of the rod. $A$ uniform magnetic field $B = 2\,T$ exists in a direction perpendicular to the plane of motion. Then:

$A$ coil of mean area $500 \ cm^2$ and having $1000$ turns is held with its plane perpendicular to a uniform magnetic field of $0.4 \ G$. If the coil is turned through $180^{\circ}$ in $\frac{1}{10} \ s$,then the average induced emf is $(1 \ G = 10^{-4} \ T)$. (in $V$)

$A$ metallic rod of length '$L$' is rotated with an angular speed of '$\omega$' normal to a uniform magnetic field '$B$' about an axis passing through one end of the rod,as shown in the figure. The induced emf will be: