RL and RC Series Circuits

An inductor of self inductance $1$H connected in series with a resistor of $100\pi\ \Omega$ and an a.c. supply of $100\pi$V, $50$ Hz. Maximum current flowing in the circuit in ampere is

In a L-R circuit of 4 mH inductance and $3\ \Omega$ resistance, e.m.f. $E = \cos(1000t)$ V is applied. The amplitude of current is

In an a.c. circuit, a resistance R is connected in series with an inductance 'L'. If phase angle between voltage and current is $45^\circ$, the value of inductive reactance will be

($\sin 45^\circ = \frac{1}{\sqrt{2}} = \cos 45^\circ$)

A coil of self inductance $L$ is connected in series with a bulb B and an a.c. source. Brightness of the bulb decreases when

An electric lamp connected in series with a capacitor and an a.c source is glowing with certain brightness. On reducing the frequency of source the brightness of the lamp

When an inductance '$L$' and resistor '$R$' are connected in series to $25$V, $50$ Hz supply, a current of $0.5$ A flows in the circuit. The current lags behind in phase from applied voltage by $\left(\frac{\pi}{3}\right)$ radian. The value of R is $\left(\cos 60^\circ = \frac{1}{2}\right)$

An inductor stores 16 J of magnetic field energy and dissipates 32 W of thermal energy due to its resistance when an a.c. current of 2 A (rms) and frequency 50 Hz flows through it. The ratio of inductive reactance to its resistance is ______. ($\pi = 3.14$)

A series combination of resistor 'R' and capacitor 'C' is connected to an a.c. source of angular frequency '$\omega$'. Keeping the voltage same, if the frequency is changed to $\left(\frac{\omega}{3}\right)$ the current becomes half of the original current. Then the ratio of capacitive reactance and resistance is

A light bulb connected in series with a capacitor and an a.c.source is glowing with certain brightness. On reducing the value of capacitance and frequency respectively, the brightness of the bulb

An a.c. source of angular frequency $\omega$ is connected across a resistor $R$ and a capacitor $C$ in series. The current is observed as $I$. Now the frequency of the source is changed to $\omega/4$, (keeping the voltage unchanged) the current is found to be $I/3$. The ratio of resistance to reactance at frequency $\omega$ is

In an $LR$ circuit, the value of $L$ is $\left(\frac{0.3}{\pi}\right)$ henry and the value of R is $40\ \Omega$, If in the circuit, an alternating e.m.f of 230 V at 50 cycles per second is connected, the impedance of the circuit and current will be respectively

In an a.c. circuit, a resistance ' $R$ ' is connected in series with an inductance ' $L$ '. If phase angle between voltage and current is $45^\circ$, the value of inductive reactance will be $(\tan 45^\circ = 1)$

An a.c. source of frequency ' f ' is connected to a circuit containing an inductance ' $L$ ' and resistance ' R ' in series. The impedance of this circuit is

An ideal inductor of $\left(\frac{1}{\pi}\right)\text{H}$ is connected in series with a $300\ \Omega$ resistor. If a $20\text{ V},\ 200\text{ Hz}$ alternating source is connected across the combination, the phase difference between the voltage and current is

A resistance of $200\ \Omega$ and an inductor of $\frac{1}{2\pi}\text{ H}$ are connected in series to a.c. voltage of 40 V and 100 Hz frequency. The phase angle between the voltage and current is

A coil of resistance $450\ \Omega$ and self-inductance 1.5 henry is connected to an a.c. source of frequency $\frac{150}{\pi}\text{ Hz}$. The phase difference between voltage and current is

An inductor of self inductance 1 H is connected in series with a resistor of $100\pi$ ohm and an ac supply of $100\pi$ volt, 50 Hz. Maximum current flowing in the circuit is _________ A.

A coil of self-inductance $L$ is connected in series with a bulb and an a. c. source. Brightness of the bulb decreases when

For ac circuit shown in figure, $R = 100\text{ k}\Omega$ and $C = 100\text{ pF}$ and the phase difference between $V$in and $(V_B - V_A)$ is $90^\circ$. The input signal frequency is $10^{x}\text{ rad/sec}$, where ' $x$ ' is __________.

In an a.c. circuit, the reactance of a coil is $\sqrt{3}$ times its resistance. The phase difference between the voltage across the coil to the current through the coil will be

An electric lamp connected in series with a capacitor and an a.c. source is glowing with certain brightness. On increasing the value of capacitance the brightness of the lamp

A coil of self inductance L is connected in series with a bulb B and an a.c. source. Brightness of the bulb decreases when

A bulb and a capacitor are connected in series across an ac supply. A dielectric is then placed between the plates of the capacitor. The glow of the bulb:

An inductance coil has a resistance of $80\ \Omega$. When on AC signal of frequency 480 Hz is applied to the coil, the voltage leads the current by $45^\circ$. The inductance of the coil in henry is

$\left[\sin 45^\circ = \cos 45^\circ = 1/\sqrt{2}\right]$

A coil of negligible resistance is connected in series with $90\ \Omega$ resistor across $120\text{ V},\ 60\text{ Hz}$ supply. A voltmeter reads $36\text{ V}$ across resistance. Inductance of the coil is:

An a.c. voltage source $V = V_0 \sin \omega t$ is connected across resistance ' $R$ ' and capacitance ' $C$ ' in series. It is given that $R = \frac{1}{\omega C}$ and the peak current is $I_0$. If the angular frequency of the voltage source is changed to $\left(\frac{\omega}{\sqrt{3}}\right)$, then the new peak current in the circuit is

When a coil is connected to a d.c. source of e.m.f. 12 volt; then the current of 4 A flows in it. If the same coil is connected to a 12 volt, 50 Hz a.c. source, then the current flowing in it is 2.4 A. Then self-inductance of the coil will be

When 100 V d.c. is applied across a solenoid, a current of 1 A flows in it. When 100 a.c. is applied across it, the current drops to 0.5 A. If the frequency is 50 Hz, the impedance and inductance is

When 80 volt d.c. is applied across a solenoid, a current of 0.8 A flows in it. When 80 volt a.c. is applied across the same solenoid, the current becomes 0.4 A. If the frequency of a.c. source is 50 Hz, the impedance and inductance of the solenoid is nearly

When a coil is connected across a $20\text{ V}$ dc supply, it draws a current of $5\text{ A}$. When it is connected across $20\text{ V},\ 50\text{ Hz}$ ac supply, it draws a current of $4\text{ A}$. The self inductance of the coil is __________ $\text{mH}$. (Take $\pi = 3$)

When a dc voltage of $100\text{ V}$ is applied to an inductor, a dc current of $5\text{ A}$ flows through it. When an ac voltage of $200\text{ V}$ peak value is connected to inductor, its inductive reactance is found to be $20\sqrt{3}\ \Omega$. The power dissipated in the circuit is _________ W.

A light bulb connected in series with a capacitor and an a.c. source is glowing with a certain brightness. On reducing the capacitance of the capacitor and the frequency of the source, the brightness of the lamp (respectively)

A coil having an inductance of $\frac{1}{\pi}\text{ H}$ is connected in series with a resistance of $300\ \Omega$. If $20\text{ V}$ from a $200\text{ Hz}$ source are impressed across the combination, the value of the phase angle between the voltage and the current is

An e.m.f. $E = 4\cos(1000t)$ volt is applied to an LR circuit of inductance $3\text{ mH}$ and resistance $4\ \Omega$. The maximum current in the circuit is

When an inductor '$L$' and a resistor '$R$' in series are connected across a $15\text{ V},\ 50\text{ Hz}$ a.c. supply, a current of $0.3\text{ A}$ flows in the circuit. The current differs in phase from applied voltage by $\left(\frac{\pi}{3}\right)^{c}$. The value of '$R$' is $\left(\sin\frac{\pi}{6} = \cos\frac{\pi}{3} = \frac{1}{2},\ \sin\frac{\pi}{3} = \cos\frac{\pi}{6} = \frac{\sqrt{3}}{2}\right)$

An a.c. source of $15\text{ V},\ 50\text{ Hz}$ is connected across an inductor (L) and resistance (R) in series R.M.S. current of $0.5\text{ A}$ flows in the circuit. The phase difference between applied voltage and current is $\left(\frac{\pi}{3}\right)$ radian. The value of resistance $(R)$ is $\left(\tan 60^\circ = \sqrt{3}\right)$

A coil having an inductance of $\frac{1}{\pi}\text{ H}$ is connected in series with a resistance of $300\ \Omega$. If A.C. Source $(20\text{ V} - 200\text{ Hz})$ is connected across the combination, the phase angle between voltage and current is

In an a.c. circuit, a resistance R = 40 $\Omega$ and an inductance 'L' are connected in series. If the phase angle between voltage and current is 45 ${}^\circ$, then the value of the inductive reactance is (tan 45${}^\circ$ = 1)

An inductive coil has a resistance of $100\ \Omega$. When an a.c. signal of frequency $1000\text{ Hz}$ is applied to the coil the voltage leads the current by $45^\circ$. The inductance of the coil is $(\tan 45^\circ = 1$)

A 0.07 H inductor and a 12$\Omega$ resistor are connected in series to a 220V, 50 Hz ac source. The approximate current in the circuit and the phase angle between current and source voltage are respectively. [Take $\pi$ as $\frac{22}{7}$ ]

An a.c. source of angular frequency '$\omega$' is fed across a resistor '$R$' and a capacitor '$C$' in series. The current registered is I. If now the frequency of source is changed to $\frac{\omega}{3}$ (but maintaining the same voltage), the current in the circuit is found to be halved. The ratio of reactance to resistance at the original frequency '$\omega$' will be

A series combination of resistor 'R' and capacitor 'C' is connected to an a.c. source of angular frequency '$\omega$'. Keeping the voltage same, if the frequency is changed to $\frac{\omega}{3}$ the current becomes half of the original current. Then the ratio of capacitive reactance and resistance at the former frequency is

When a d.c. voltage of $200\text{ V}$ is applied to a coil of self-inductance $\left(\frac{2\sqrt{3}}{\pi}\right)\text{ H}$, a current of $1\text{ A}$ flows through it. But by replacing d.c. source with a.c. source of $200\text{ V}$, the current in the coil is reduced to $0.5\text{ A}$. Then the frequency of a.c. supply is

An inductor coil takes current 8A when connected to an 100 V and 50 Hz a.c. source. A pure resistor under the same condition takes current of 10A. If inductor coil and resistor are connected in series to an 100V and 40 Hz a.c. supply, then the current in the series combination of above resistor and inductor is

An AC circuit contains resistance of $12\ \Omega$ and inductive reactance $5\ \Omega$. The phase angle between current and potential difference will be

A light bulb and an inductor coil are connected to an ac source through a key as shown in the figure below. The key is closed and after sometime an iron rod is inserted into the interior of the inductor. The glow of the light bulb

An inductance coil has an impedance of 100 $\Omega$. When an AC signal of frequency 1000 Hz is applied to the coil, the applied voltage leads the current by 45°. The self-inductance of the coil is

A circuit when connected to an AC source of 12 V gives a current of 0.2 A. The same circuit when connected to a DC source of 12 V, gives a current of 0.4 A. The circuit is

A circuit connected to an ac source of emf e = e0sin(100t) with t in seconds, gives a phase difference of $\pi$/4 between the emf e and current i. Which of the following circuits will exhibit this?

A series LR circuit is connected to a voltage source with

V(t) = V0 sin$\Omega$t. After very large time, current I(t) behaves as

(t0 >> $\frac{L}{R}$):

A series R-C circuit is connected to an alternating voltage source. Consider two situations: (a) When capacitor is air filled.

(a) When capacitor is mica filled. Current through resistor is $I$ and voltage across capacitor is $V$ then

A coil of self-inductance L is connected in series with a bulb B and an AC source. Brightness of the bulb decreases when

An ac voltage is applied to a resistance R and an inductor L in series. If R and the inductive reactance are both equal to 3 $\Omega$, the phase difference between the applied voltage and the current in the circuit is

A coil has resistance 30 ohm and inductive reactance 20 ohm at 50 Hz frequency. If an ac source, of 200 volt, 100 Hz, is connected across the coil, the current in the coil will be