If a coil of metal wire is kept stationary in a non-uniform magnetic field, then

The coil of area $0.1 \ m^2$ has $500$ turns. After placing the coil in a magnetic field of strength $4 \times 10^{-4} \ Wb/m^2$,if it is rotated through $90^o$ in $0.1 \ s$,the average emf induced in the coil is......$V$

According to Faraday's law of electromagnetic induction:

The north pole of a magnet is falling towards a metallic ring as shown in the figure. If looked at from above the ring,the direction of the induced current will be:

$A$ magnetic field $B = 2t + 4t^{2}$ (where $t$ is time) is applied perpendicular to the plane of a circular wire of radius $r$ and resistance $R$. If all units are in $SI$, the electric charge that flows through the circular wire during $t = 0 \ s$ to $t = 2 \ s$ is:

$A$ coil of resistance $400 \,\Omega$ is placed in a magnetic field. If the magnetic flux $\phi \,(Wb)$ linked with the coil varies with time $t \,(s)$ as $\phi = 50t^2 + 4$,the current in the coil at $t = 2 \,s$ is.....$A$.