Shown in the figure is a circular loop of radius $r$ and resistance $R$. $A$ variable magnetic field of induction $B = B_0 e^{-t}$ is established inside the coil. If the key $K$ is closed,the electrical power developed right after closing the switch is equal to

The figure shows a circuit that contains three identical resistors with resistance $R = 9.0 \,\Omega$ each,two identical inductors with inductance $L = 2.0 \,mH$ each,a capacitor $C$,and an ideal battery with $emf \,\varepsilon = 18 \,V$. The current $i$ through the battery just after the switch is closed is:

$A$ circular coil of $500$ turns of wire has an enclosed area of $0.1\,m^2$ per turn. It is kept perpendicular to a magnetic field of induction $0.2\,T$ and rotated by $180^o$ about a diameter perpendicular to the field in $0.1\,s$. How much charge will pass when the coil is connected to a galvanometer with a combined resistance of $50\,\Omega$?

$A$ square loop of side $12 \; cm$ with its sides parallel to $X$ and $Y$ axes is moved with a velocity of $8 \; cm \, s^{-1}$ in the positive $x$-direction in an environment containing a magnetic field in the positive $z$-direction. The field is neither uniform in space nor constant in time. It has a gradient of $10^{-3} \; T \, cm^{-1}$ along the negative $x$-direction (that is, it increases by $10^{-3} \; T \, cm^{-1}$ as one moves in the negative $x$-direction), and it is decreasing in time at the rate of $10^{-3} \; T \, s^{-1}$. Determine the direction and magnitude of the induced current in the loop if its resistance is $4.50 \; m\Omega$.

$A$ part of a complete circuit is shown in the figure. At some instant,the value of current $I$ is $1\, A$ and it is decreasing at a rate of $10^{2}\, A s^{-1}$. The value of the potential difference $V_{P} - V_{Q}$ (in volts) at that instant is:

$A$ conducting loop of finite resistance lies on the $x-y$ plane. There is a constant magnetic field in the $z$ direction. The area of the loop varies with time $t$, as $A = A_0 (1 + \sin t)$ in appropriate units. The figure that correctly indicates the qualitative behaviour of the power $P$ dissipated in the loop as a function of time is :