The magnetic flux linked with a coil (in $Wb$) is given by the equation $\phi = 5t^2 + 3t + 16$. The magnitude of induced emf in the coil at the fourth second will be (in $V$):

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 ......... $V$.

The magnetic flux through a coil perpendicular to its plane and directed into the paper is varying according to the relation $\phi = 5t^2 + 10t + 5$ milliweber. The $e.m.f.$ induced in the loop after $5 \, s$ is ..... $V$.

$A$ 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 . . . . . . $C$.

An electron moves on a straight line path $XY$ as shown. The $abcd$ is a coil adjacent to the path of the electron. What will be the direction of current,if any,induced in the coil?

The Lenz law is associated with