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 $V$):

As a result of a change in the magnetic flux linked to the closed loop as shown in the figure,an $e.m.f.$ $V$ volt is induced in the loop. The work done (in joule) in taking a charge $Q$ coulomb once along the loop is

$A$ coil having effective area '$A$' is held with its plane normal to a magnetic field of induction '$B$'. The magnetic induction is quickly reduced to $25\%$ of its initial value in $1 \text{ s}$. The e.m.f. induced in the coil (in volt) will be

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

$A$ conducting ring of certain resistance is falling towards a current-carrying straight long conductor. The ring and conductor are in the same plane. Then

Magnetic flux (in weber) in a closed circuit of resistance $20\,\Omega$ varies with time $t(s)$ as $\phi = 8t^2 - 9t + 5$. The magnitude of the induced current at $t = 0.25\,s$ will be $...mA$.