The magnetic flux through a stationary loop with resistance $R$ varies during an interval of time $T$ as $\phi = at(T - t)$. The heat generated during this time,neglecting the inductance of the loop,will be

$A$ system $S$ consists of two coils $A$ and $B$. The coil $A$ carries a steady current $I$. The coil $B$ is suspended nearby as shown in the figure. If the system is heated,so as to raise the temperature of the two coils steadily,then:

$A$ coil with an area of $500 \ cm^2$ and $1000$ turns is placed in a magnetic field of $2 \times 10^{-5} \ Wb/m^2$ perpendicular to its plane. If the coil is rotated by $180^o$ in $0.2 \ s$,the induced $emf$ in $milli-volts$ is:

$A$ $50$ turns circular coil has a radius of $3\;cm$. It is kept in a magnetic field acting normal to the area of the coil. The magnetic field $B$ increases from $0.10\;T$ to $0.35\;T$ in $2\;ms$. The average induced $e.m.f.$ in the coil is.......$V$.

$A$ circular coil of area $100 \,cm^2$ and $20$ turns is kept in a magnetic field of flux density $2 \,Wb/m^2$. It rotates from a position where its plane makes an angle of $30^{\circ}$ with the field to a position perpendicular to the field in a time $0.2 \,s$. Find the magnitude of the emf induced in the coil due to its rotation. (in $V$)

$A$ rectangular coil of $20$ turns and an area of cross-section $25 \, cm^2$ has a resistance of $100 \, \Omega$. If a magnetic field which is perpendicular to the plane of the coil changes at the rate of $1000 \, T/s$,the current in the coil is $....... \, A$.