The magnetic flux through a coil is $4 \times 10^{-4} \ Wb$ at time $t=0$. It reduces to $30 \%$ of its original value in time $t$ seconds. If the e.m.f. induced in the coil is $0.56 \ mV$,then the value of $t$ is: (in $s$)

$A$ circular loop of wire is in the same plane as an infinitely long wire carrying a constant current $i$. Four possible motions of the loop are marked by $N, E, W$,and $S$ as shown below. $A$ clockwise current is induced in the loop when the loop is pulled towards:

In the above diagram,a strong bar magnet is moving towards solenoid-$2$ from solenoid-$1$. The direction of induced current in solenoid-$1$ and that in solenoid-$2$,respectively,are through the directions:

$A$ coil having $500$ square loops each of side $10\, cm$ is placed normal to a magnetic flux which increases at the rate of $1.0\, T/s$. The induced $e.m.f.$ in volts is:

Two identical circular loops of metal wire are lying on a table without touching each other. Loop $A$ carries a current which increases with time. In response,the loop $B$:

$A$ coil having $n$ turns and resistance $R \ \Omega$ is connected with a galvanometer of resistance $4 R \ \Omega$. This combination is moved in time $t$ seconds from a magnetic flux $\phi_1$ Weber to $\phi_2$ Weber. The induced current in the circuit is