Lenz's law is expressed by the following formula (here $e$ = induced $e.m.f.$,$\phi$ = magnetic flux in one turn and $N$ = number of turns).

$A$ long solenoid with $15$ turns per $cm$ has a small loop of area $2.0 \,cm^2$ placed inside the solenoid normal to its axis. If the current carried by the solenoid changes steadily from $2.0 \,A$ to $4.0 \,A$ in $0.1 \,s$, the induced emf in the loop while the current is changing is nearly [Take $\pi=3.14$].

$A$ coil having $n$ turns and resistance $R$ is connected with a galvanometer of resistance $2R$. This combination is moved in time $t$ from flux $\phi_1$ to $\phi_2 \ Wb$. The induced current in the circuit is

$A$ $50$ turns circular coil has a radius of $3\;cm$. It is kept in a magnetic field acting normal to the area of the coil. The magnetic field $B$ increases from $0.10\;T$ to $0.35\;T$ in $2\;ms$. The average induced $e.m.f.$ in the coil is.......$V$.

Two different loops are concentric and lie in the same plane. The current in the outer loop is clockwise and increasing with time. The induced current in the inner loop then,is

$A$ wire of irregular shape is turning into a circular shape in a magnetic field which is directed into the paper. The direction of the induced current is