A coil of mean area $500{\mathrm{c}\mathrm{m}}^2$ and having $1000$ turns is held perpendicular to a uniform field of $0.4$ gauss. The coil is turned through $180°$ in $\frac{1}{10}$ second. The average induced $\mathrm{e}\mathrm{m}\mathrm{f}$ is

Consider a metal ring kept on a horizontal plane. A bar magnet is held above the ring with its length along the axis of the ring. If the magnet is dropped freely the acceleration of the falling magnet is (g is acceleration due to gravity) : 

An electron beam is moving near to a conducting loop then the induced current in the loop :-

An aluminium ring B faces an electromagnet A. The current I through A can be altered. Then which of the following statement is correct :-