Magnetic flux $\phi$ (in weber) linked with a closed circuit of resistance $10\, \Omega$ varies with time $t$ (in seconds) as $\phi = 5t^2 - 4t + 1$. The induced electromotive force in the circuit at $t = 0.2\, s$ is ......... $V$.

An infinitely long cylinder is kept parallel to a uniform magnetic field $B$ directed along the positive $z$-axis. The direction of induced current as seen from the $z$-axis will be

$A$ coil of surface area $200 \ cm^2$ having $25$ turns is held perpendicular to the magnetic field of intensity $0.02 \ Wb/m^2$. The resistance of the coil is $1 \ \Omega$. If it is removed from the magnetic field in $1 \ s$,the induced charge in the coil is . . . . . . $C$.

$A$ coil of $n$ turns and area $A$ is suddenly removed from a magnetic field,and a charge $q$ flows through the coil. If the resistance of the coil is $R$,then the magnetic flux density is (in $Wb/m^2$):

The magnetic flux through a coil is $4 \times 10^{-4} \ Wb$ at time $t=0$. It reduces to $30 \%$ of its original value in time $t$ seconds. If the e.m.f. induced in the coil is $0.56 \ mV$,then the value of $t$ is: (in $s$)

The magnetic flux through a coil perpendicular to its plane and directed into the paper is varying according to the relation $\phi = (2t^2 + 4t + 6) \, mWb$. The $emf$ induced in the loop at $t = 4 \, s$ is ....... $V$.