Radio frequency choke uses a core of

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

In an $L-R$ circuit connected to a battery,the rate at which energy is stored in the inductor is plotted against time during the growth of the current in the circuit. Which of the following best represents the resulting curve?

In a coil of resistance $10\,\Omega$,the induced current developed by changing magnetic flux through it is shown in the figure as a function of time. The magnitude of change in flux through the coil in weber is:

$A$ 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:

$A$ square loop of side $0.1 \, m$ and resistance $1 \, \Omega$ is moved with a constant velocity in a magnetic field of $2 \, Wb/m^2$. If a current of $1 \, mA$ is induced in the circuit, what is the velocity of the loop in $cm/sec$? (The external circuit consists of a Wheatstone bridge with five $3 \, \Omega$ resistors as shown in the figure.)