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 $...mA$.

On which factor does the induced charge depend?

$A$ conducting square loop of side $l$ and resistance $R$ moves in its plane with a uniform velocity $v$ perpendicular to one of its sides. $A$ uniform and constant magnetic field $B$ exists perpendicular to the plane of the loop as shown in the figure. The current induced in the loop is

Assertion $(A)$: It is more difficult to move a magnet into a coil with more loops.
Reason $(R)$: This is because the emf induced in each current loop resists the motion of the magnet.

The magnetic flux through a coil of resistance $10\,\Omega$ is changed by $\Delta \phi$ in $0.1\,s$. The resulting current in the coil varies with time as shown in the figure. Then,the magnitude $\left| \Delta \phi \right|$ is equal to (in weber):

The north pole of a long horizontal bar magnet is being brought closer to a vertical conducting plane along the perpendicular direction. The direction of the induced current in the conducting plane will be