Inductors & DC Transients (Mixed)

Two coils P and S have a mutual inductance of ($\pi$) mH. The secondary coil S has resistance $4\ \Omega$ and self inductance $(60/\pi)$ mH. If the current in the primary is $I_p = 12\sin(50\pi t)$, then the maximum value of the current induced in coil S is [Take $\pi^2 = 10$]

Three inductances are connected as shown in figure. The equivalent inductance is

A $100\text{ mH}$ coil carries a current of $1\text{ A}$. Energy stored in the form of magnetic field is

The magnetic energy stored in an inductor of inductance $4\,\mu\text{H}$ carrying a current of $2\text{ A}$ is:

A coil has an inductance of $2\text{ H}$ and resistance of $4\ \Omega$. A $10\text{ V}$ is applied across the coil. The energy stored in the magnetic field after the current has built up to its equilibrium value will be ___________ $\times 10^{-2}\text{ J}$.

In the given figure, an inductor and a resistor are connected in series with a battery of emf E volt. $\frac{E^a}{2b}\text{ J/s}$ represents the maximum rate at which the energy is stored in the magnetic field (inductor). The numerical value of $\frac{b}{a}$ will be __________.

A coil of inductance 1 H and resistance $100\ \Omega$ is connected to a battery of 6 V. Determine approximately:

(a) The time elapsed before the current acquires half of its steady - state value.

(b) The energy stored in the magnetic field associated with the coil at an instant 15 ms after the circuit is switched on. (Given $\ln 2 = 0.693,\ e^{-3/2} = 0.25$)

Three pure inductors each of inductance 6H are connected as shown in the figure. Their equivalent inductance between the points 'P' and 'Q' is

For the given circuit the current i through the battery when the key is closed and the steady state has been reached is __________.

An inductor of 10 mH is connected to a 20V battery through a resistor of 10 k$\Omega$ and a switch. After a long time, when maximum current is set up in the circuit, the current is switched off. The current in the circuit after 1 $\mu$s is $\frac{x}{100}$ mA. Then x is equal to ___________. (Take e______1 = 0.37)

In the part of an a.c. circuit as shown, the resistance $R = 0.2\,\Omega$. At a certain instant $(V_A - V_B) = 0.5\text{ V},\ I = 0.5\text{ A}$ and $\frac{\Delta I}{\Delta t} = 8\text{ A/s}$. The inductance of the coil is

An inductor coil wound uniformly has self inductance 'L' and resistance 'R'. The coil is broken into two identical parts. The two parts are then connected in parallel across a battery of 'E' volt of negligible internal resistance. The current through battery at steady state is

Consider an electrical circuit containing a two way switch 'S'. Initially S is open and then T1 is connected to T2. As the current in R = 6$\Omega$ attains a maximum value of steady state level, T1 is disconnected from T2 and immediately connected to T3. Potential drop across r = 3$\Omega$ resistor immediately after T1 is connected to T3 is __________ V. (Round off to the Nearest Integer)

An RC circuit as shown in the figure is driven by a AC source generating a square wave. The output wave pattern monitored by CRO would look close to:

The current (i) at time t = 0 and t = $\infty$ respectively for the given circuit is:

A series L-R circuit is connected to a battery of emf V. If the circuit is switched on at t = 0, then the time at which the energy stored in the inductor reaches $\left(\frac{1}{n}\right)$ times of its maximum value, is:

An emf of 20 V is applied at time t = 0 to a circuit containing in series 10 mH inductor and 5 $\Omega$ resistor. The ratio of the currents at time t = $\infty$ and at t = 40 s is close to: (Take e2 = 7.389)

A coil of self inductance 10 mH and resistance 0.1 $\Omega$ is connected through a switch to a battery of internal resistance 0.9 $\Omega$. After the switch is closed, the time taken for the current to attain 80% of the saturation value is: [take ln 5 = 1.6]

In the figure shown, a circuit contains two identical resistors with resistance R = 5$\Omega$ and an inductance with L = 2mH. An ideal battery of 15 V is connected in the circuit. What will be the current through the battery long after the switch is closed?

Consider the LR circuit shown in the figure. If the switch S is closed at t = 0 then the amount of charge that passes through the battery between t = 0 and t = $\frac{L}{R}$ is:

In the circuit shown,

the switch S1 is closed at time t = 0 and the switch S2 is kept open. At some later time(t0), the switch S1 is opened and S2 is closed. The behavior of the current I as a function of time 't' is given by:

The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA. This inductor is of inductance

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, and an ideal battery with emf $\varepsilon = 18\text{ V}$. The current $i$ through the battery just after the switch is closed is

In the circuits (a) and (b) switches S1 and S2 are closed at t = 0 and are kept closed for a long time. The variation of currents in the two circuits for t $\geq$ 0 are roughly shown by (figures are schematic and not drawn to scale):

An inductor $(L = 0.03\text{ H})$ and a resistor $(R = 0.15\text{ k}\Omega)$ are connected in series to a battery of $15\text{ V}\ \text{EMF}$ in a circuit shown below. The key $K_1$ has been kept closed for a long time. Then at $t = 0,\ K_1$ is opened and key $K_2$ is closed simultaneously. At $t = 1\text{ ms},$ the current in the circuit will be: $\left(e^5 \cong 150\right)$

In the circuit shown here, the point $'C'$ is kept connected to point $'A'$ till the current flowing through the circuit becomes constant. Afterward, suddenly, point $'C'$ is disconnected from point $'A'$ and connected to point $'B'$ at time $t = 0.$ Ratio of the voltage across resistance and the inductor at $t = L/R$ will be equal to:

In an $LCR$ circuit as shown below both switches are open initially. Now switch $S_1$ is closed, $S_2$ kept open. ($q$ is charge on the capacitor and $\tau = RC$ is Capacitance time constant). Which of the following statements is correct?

The current $(I)$ in the inductance is varying with time according to the plot shown in figure.

Which one of the following is the correct variation of voltage with time in the coil?

In the circuit shown below, the key $K$ is closed at $t = 0.$ The current through the battery is

An inductor of inductance $L = 400\text{ mH}$ and resistors of resistance $R_1 = 2\ \Omega$ and $R_2 = 2\ \Omega$ are connected to a battery of $\text{emf } 12\text{ V}$ as shown in the figure. The internal resistance of the battery is negligible. The switch $S$ is closed at $t = 0.$ The potential drop across $L$ as a function of time is:

A coil of 40 henry inductance is connected in series with a resistance of 8 ohm and the combination is joined to the terminals of a 2 volt battery. The time constant of the circuit is

In a circuit inductance $L$ and capacitance $C$ are connected as shown in figure. $A_1$ and $A_2$ are ammeters. When key $K$ is pressed to complete the circuit, then just after closing key $(K)$, the reading of current will be