The current $i$ in an induction coil varies with time $t$ according to the graph shown in the figure. Which of the following graphs shows the induced emf $(E)$ in the coil with time?

Radio frequency choke uses a core of

Two different coils have inductances $L_1 = 4 \ mH$ and $L_2 = 2 \ mH$. At a certain instant,the current in the two coils is increasing at the same constant rate,and the power supplied to the first coil is four times that of the second coil. If $e$,$I$,and $U$ indicate the potential difference,current,and energy stored in the inductance respectively,then which of the following is correct?

$A$ coil of self-inductance $L$ is connected at one end of two rails as shown in the figure. $A$ connector of length $l$ and mass $m$ can slide freely over the two parallel rails. The entire setup is placed in a magnetic field of induction $B$ directed into the page. At an instant $t = 0$,an initial velocity $v_0$ is imparted to the connector,and as a result,it starts moving along the $x$-axis. Which of the following graphs best represents the displacement $x$ of the connector as a function of time $t$?

Two similar circular loops carry equal currents in the same direction. On moving the coils further apart,the electric current will

The plane of a circular coil of resistance $7.5 \ \Omega$ is placed perpendicular to a uniform magnetic field. The flux $\phi$ (in weber) through the coil varies with time $t$ (in second) as $\phi = 2t^2 + 3t - 2$. The induced power in the coil at time $t = 3 \ s$ is (in $W$)