Growth and Decay of Current in an L-R Circuit : Growth of Current

Switch $S$ of the circuit shown in figure is closed at $t=0$. If $e$ denotes the induced $\mathrm{emf}$ in $L$ and $i$, the current flowing through the circuit at time $t$, which of the following graphs is correct?

The current in an $L$-$R$ circuit builds upto $\frac{3}{4}\mathrm{th}$ of its steady state value in $4 \mathrm{s}$. The time constant of this circuit is

The network shown in the figure is a part of a complete circuit. If at a certain instant the current $i$ is $5 \mathrm{A}$ and decreasing at the rate of ${10}^3 \mathrm{A} {\mathrm{s}}^{-1}$ then, $V_{\mathrm{B}}-V_{\mathrm{A}}$ is

The value of time constant for the given circuit is 

In the circuit shown in figure the jockey $J$ is being pulled towards right so that the resistance in the circuit is increasing. Its a value at some instant is $5 \mathrm{\Omega }$. The current in the circuit at this instant will be

An emf of $15 \mathrm{V}$ is applied in a circuit coil containing $5 \mathrm{H}$ inductance and $10 \mathrm{\Omega }$ resistance. The ratio of the currents at time $t=\infty$ and $t=1 \mathrm{s}$ is

When the current in the portion of the circuit shown in the figure is $2 \mathrm{A}$ and increasing at the rate of $1 \mathrm{A} {\mathrm{s}}^{-1}$, the measured potential difference $V_{\mathrm{ab}}=8 \mathrm{V}$. However when the current is $2 \mathrm{A}$ and decreasing at the rate of $1 \mathrm{A} {\mathrm{s}}^{-1}$, the measured potential difference $V_{\mathrm{ab}}=4 \mathrm{V}$. The values of $R$ and $L$ are

Figure shows two bulbs $B_1$ and $B_2$ resistor $R$ and inductor $L$, when the switch $S$ is turned off

An inductor $L$, a resistance $R$ and two identical bulbs, $B_1$ and $B_2$ are connected to a battery through a switch $S$ as shown in the figure. Which of the following statements gives the correct description of the happenings, when the switch $S$ is closed?

A coil and a bulb are connected in series with a $\mathrm{DC}$ source, a soft iron core is, then inserted in the coil, then

If $L,C$ and $R$ represent, the physical quantities inductance, capacitance and resistance respectively, only the following combination does not have the dimensions of frequency

In the following figure, what is the final value of current in the $10 \mathrm{\Omega }$ resistor when the plug of key $K$ is inserted?

In the circuit shown, what is the energy stored in the coil at steady state?

An emf of $20 \mathrm{V}$ is applied in a circuit coil containing $5 \mathrm{H}$ inductance and $5 \mathrm{\Omega }$ resistance. The ratio of the currents at time $t=\infty$ and $t=\ln \left(2\right)$ is

The time constant of an inductance coil is $2.0\times {10}^{-3} \mathrm{s}$. When a $90 \mathrm{\Omega }$ resistance is joined in series, the time constant becomes $0.5\times {10}^{-3} \mathrm{s}$. The inductance and resistance of the coil are

In the circuit shown in the figure, what is the value of $I_1$ just after pressing the key $K?$

An $L$-$R$ circuit with a battery is connected at $t=0$. Which of the following quantities is not zero just after the connection?

During current growth in an $L$-$R$ circuit the time constant is the time in which the magnitude of current becomes

An inductor of $2 \mathrm{H}$ and a resistance of $10 \mathrm{\Omega }$ are connected in series with a battery of $5 \mathrm{V}$. The initial rate of change in current is

A coil of inductance $300 \mathrm{mH}$ and resistance $2 \mathrm{\Omega }$ is connected to a source of voltage $2 \mathrm{V}$. The current reaches half of its steady state value in