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Alternating Current — JEE Main & Advanced Physics PYQs

411 previous year questions from Alternating Current with answers and solutions. Numbered list, year tags, and one-tap solutions — built for serious JEE / NEET practice.

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1

Consider a circuit consisting of a capacitor of capacitance C and a coil with N turns per unit length, cross sectional area S and length d , where d^2 S . There is another coil of

JEE Advanced 2026 Solution View → 2

An LCR series circuit driven with E_ rms = 90 V at frequency f_d = 30 Hz has resistance R = 80 , , an inductance with inductive reactance X_L = 20.0 , and capacitance with capacitiv

JEE Main 2026 Solution View → 3

A series LCR circuit with R = 20 , L = 1.6 H and C = 40 F is connected to a variable frequency a.c. source. The inductive reactance at resonant frequency is _______ .

JEE Main 2026 Solution View → 4

An a.c. source of angular frequency 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 /4 ,

JEE Main 2026 Solution View → 5

An inductor of 10 mH, capacitor of 0.1 F and a resistor of 100 are connected in series across an a.c power supply 220 V, 70 Hz. The power factor of the given circuit is 0.5 . The d

JEE Main 2026 Solution View → 6

The figure given below shows an LCR series circuit with two switches S₁ and S₂ . When switch S₁ is closed keeping S₂ open, the phase difference ( ) between the current and source v

JEE Main 2026 Solution View → 7

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.

JEE Main 2026 Solution View → 8

The electric current in the circuit is given as i=i_ o (t / T) . The r.m.s current for the period t=0 to t=T is _ _ _ _ .

JEE Main 2026 Solution View → 9

For the series L C R circuit connected with 220 ~V , 50 ~Hz a.c source as shown in the figure, the power factor is 10 . The value of is _ _ _ _ .

JEE Main 2026 Solution View → 10

Using a variable frequency a.c. voltage source the maximum current measured in the given LCR circuit is 50 mA for V=5 (100 t) The values of L and R are shown in the figure. The cap

JEE Main 2026 Solution View → 11

A capacitor C is first charged fully with potential difference of V₀ and disconnected from the battery. The charged capacitor is connected across an inductor having inductance L .

JEE Main 2026 Solution View → 12

A circuit with an electrical load having impedance Z is connected with an AC source as shown in the diagram. The source voltage varies in time as V(t)=300 (400 t) V , where t is ti

JEE Advanced 2025 Solution View → 13

An inductor of reactance 100 , a capacitor of reactance 50 , and a resistor of resistance 50 are connected in series with an AC source of 10 V , 50 Hz. Average power dissipated by

JEE Main 2025 Solution View → 14

An ac current is represented as i =5 2 +10 (650 t + 6 ) Amp The r.m.s value of the current is

JEE Main 2025 Solution View → 15

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

JEE Main 2025 Solution View → 16

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

JEE Main 2025 Solution View → 17

An alternating current is represented by the equation, i=100 2 (100 t) ampere. The RMS value of current and the frequency of the given alternating current are

JEE Main 2025 Solution View → 18

An electric bulb rated as 100 ~W -220 ~V is connected to an ac source of rms voltage 220 V. The peak value of current through the bulb is :

JEE Main 2025 Solution View → 19

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Choke coil is simply a coil having a large inductance but

JEE Main 2025 Solution View → 20

An alternating current is given by I = I _ A t + I _ B t . The r.m.s current will be

JEE Main 2025 Solution View → 21

In a series LCR circuit, a resistor of 300 , a capacitor of 25 nF and an inductor of 100 mH are used. For maximum current in the circuit, the angular frequency of the ac source is

JEE Main 2025 Solution View → 22

A series LCR circuit is connected to an alternating source of emf E. The current amplitude at resonant frequency is I₀ . If the value of resistance R becomes twice of its initial v

JEE Main 2025 Solution View → 23

The circuit shown in the figure contains an inductor L , a capacitor C₀ , a resistor R₀ and an ideal battery. The circuit also contains two keys K ₁ and K ₂ . Initially, both the k

JEE Advanced 2024 Solution View → 24

A capacitor of reactance 4 3 and a resistor of resistance 4 are connected in series with an ac source of peak value 8 2 ~V . The power dissipation in the circuit is ________ W.

JEE Main 2024 Solution View → 25

A coil of negligible resistance is connected in series with 90 resistor across 120 ~V , 60 ~Hz supply. A voltmeter reads 36 ~V across resistance. Inductance of the coil is :

JEE Main 2024 Solution View → 26

An alternating emf E =110 2 100 t volt is applied to a capacitor of 2 F , the rms value of current in the circuit is _____ mA ,

JEE Main 2024 Solution View → 27

An LCR circuit is at resonance for a capacitor C , inductance L and resistance R . Now the value of resistance is halved keeping all other parameters same. The current amplitude at

JEE Main 2024 Solution View → 28

For a given series LCR circuit it is found that maximum current is drawn when value of variable capacitance is 25 nF . If resistance of 200 and 100 mH inductor is being used in the

JEE Main 2024 Solution View → 29

Given below are two statements: Statement I: In an LCR series circuit, current is maximum at resonance. Statement II: Current in a purely resistive circuit can never be less than t

JEE Main 2024 Solution View → 30

When a d c voltage of 100 ~V is applied to an inductor, a d c current of 5 ~A flows through it. When an ac voltage of 200 ~V peak value is connected to inductor, its inductive reac

JEE Main 2024 Solution View → 31

A series LCR circuit is subjected to an ac signal of 200 ~V , 50 ~Hz . If the voltage across the inductor ( L =10 mH ) is 31.4 ~V , then the current in this circuit is _____ .

JEE Main 2024 Solution View → 32

An ac source is connected in given series LCR circuit. The rms potential difference across the capacitor of 20 F is _____V.

JEE Main 2024 Solution View → 33

Match List I with List II Choose the correct answer from the options given below:

JEE Main 2024 Solution View → 34

In an ac circuit, the instantaneous current is zero, when the instantaneous voltage is maximum. In this case, the source may be connected to : A. pure inductor. B. pure capacitor.

JEE Main 2024 Solution View → 35

A alternating current at any instant is given by i=[6+ 56 (100 t+ / 3)] A. The r m s value of the current is ________ A.

JEE Main 2024 Solution View → 36

A transformer has an efficiency of 80 % and works at 10 V and 4 kW . If the secondary voltage is 240 V , then the current in the secondary coil is:

JEE Main 2024 Solution View → 37

A parallel plate capacitor has a capacitance C = 200 pF . It is connected to 230 V ac supply with an angular frequency 300 rad s - 1 . The rms value of conduction current in the ci

JEE Main 2024 Solution View → 38

In series LCR circuit, the capacitance is changed from C to 4 C . To keep the resonance frequency unchanged, the new inductance should be :

JEE Main 2024 Solution View → 39

An AC voltage V = 20 sin 200 π t is applied to a series LCR circuit which drives a current I = 10 sin 200 π t + π 3 . The average power dissipated is:

JEE Main 2024 Solution View → 40

An alternating voltage V ( t ) = 220 sin 100 π t volt is applied to a purely resistive load of 50 Ω . The time taken for the current to rise from half of the peak value to the peak

JEE Main 2024 Solution View → 41

A power transmission line feeds input power at 2 . 3 kV to a step down transformer with its primary winding having 3000 turns . The output power is delivered at 230 V by the transf

JEE Main 2024 Solution View → 42

A series L R circuit connected with an ac source E = ( 25 sin 1000 t ) V has a power factor of 1 2 . If the source of emf is changed to E = ( 20 sin 2000 t ) V , the new power fact

JEE Main 2024 Solution View → 43

Primary coil of a transformer is connected to 220 V A C . Primary and secondary turns of the transforms are 100 and 10 respectively. Secondary coil of transformer is connected to t

JEE Main 2024 Solution View → 44

In an a.c. circuit, voltage and current are given by: V = 100 sin ( 100 t ) V and I = 100 sin 100 t + π 3 mA respectively. The average power dissipated in one cycle is :

JEE Main 2024 Solution View → 45

In the given figure, the charge stored in 6 μ F capacitor, when points A and B are joined by a connecting wire is _______ μ C .

JEE Main 2024 Solution View → 46

A series LCR circuit with L = 100 π mH , C = 10 - 3 π F and R = 10 Ω , is connected across an AC source of 220 V , 50 Hz supply. The power factor of the circuit would be ____.

JEE Main 2024 Solution View → 47

The primary side of a transformer is connected to 230 V , 50 Hz supply. The turn ratio of primary to secondary winding is 10 : 1 . Load resistance connected to the secondary side i

JEE Main 2024 Solution View → 48

In a circuit shown in the figure, the capacitor C is initially uncharged and the key K is open. In this condition, a current of 1 A flows through the 1 Ω resistor. The key is

JEE Advanced 2023 Solution View → 49

A series LCR circuit is connected to a 45 sin ( ω t ) Volt source. The resonant angular frequency of the circuit is 10 5 rad s − 1 and current amplitude at resonance is

JEE Advanced 2023 Solution View → 50

Given below are two statements: Statement I : An AC circuit undergoes electrical resonance if it contains either a capacitor or an inductor. Statement II: An AC circuit containing

JEE Main 2023 Solution View → 51

Given below are two statements: Statement I : When the frequency of an AC source in a series LCR circuit increases, the current in the circuit first increases, attains a maximum va

JEE Main 2023 Solution View → 52

As per the given graph, choose the correct representation for curve A and curve B Where X C = Reactance of pure capacitive circuit connected with A.C. source X L = Reactance of pur

JEE Main 2023 Solution View → 53

Given below are two statements: Statement I: Maximum power is dissipated in a circuit containing an inductor, a capacitor and a resistor connected in series with an A C source, whe

JEE Main 2023 Solution View → 54

A series combination of resistor of resistance 100 Ω inductor of inductance 1 H and capacitor of capacitance 6 . 25 μF is connected to an ac source. The quality factor of

JEE Main 2023 Solution View → 55

An oscillating LC circuit consists of a 75 mH inductor and a 1 . 2 µ F capacitor. If the maximum charge to the capacitor is 2 . 7 µ C . The maximum current in the circuit

JEE Main 2023 Solution View → 56

A capacitor of capacitance 150 . 0 μ F is connected to an alternating source of emf given by E = 36 sin 120 π t V . The maximum value of current in the circuit is approxi

JEE Main 2023 Solution View → 57

An ideal transformer with purely resistive load operates at 12 kV on the primary side. It supplies electrical energy to a number of nearby houses at 120 V . The average rate of ene

JEE Main 2023 Solution View → 58

Match the List-I with List-II. List I List II A AC generator I Presence of both L and C B Transformer II Electromagnetic Induction C Resonance phenomenon to occur III Quality facto

JEE Main 2023 Solution View → 59

A series LCR circuit is connected to an ac source of 220   V ,   50   Hz . The circuit contain a resistance R = 100   Ω and an inductor of inductive reacta

JEE Main 2023 Solution View → 60

An alternating voltage source V = 260 sin ( 628 t ) is connected across a pure inductor of 5 mH . Inductive reactance in the circuit is:

JEE Main 2023 Solution View → 61

A series LCR circuit consists of R = 80 Ω . X L = 100 Ω , and X C = 40 Ω . The input voltage is 2500 cos 100 π t V . The amplitude of current, in the circuit

JEE Main 2023 Solution View → 62

An inductor of 0 . 5 mH , a capacitor of 20 μF and resistance of 20 Ω are connected in series with a 220 V ac source. If the current is in phase with the emf, the amplitu

JEE Main 2023 Solution View → 63

In the given circuit, r m s value of current I r m s through the resistor R is :

JEE Main 2023 Solution View → 64

In a series L R circuit with X L = R , power factor is P 1 . If a capacitor of capacitance C with X C = X L is added to the circuit the power factor becomes P 2 . The ratio of P 1

JEE Main 2023 Solution View → 65

For the given figures, choose the correct options:

JEE Main 2023 Solution View → 66

An inductor of inductance 2 μH is connected in series with a resistance, a variable capacitor and an AC source of frequency 7 kHz . The value of capacitance for which maximum

JEE Main 2023 Solution View → 67

A series LCR circuit is connected to an AC source of 220 V , 50 Hz . The circuit contains a resistance R = 80 Ω , an inductor of inductive reactance X L = 70 Ω , and a ca

JEE Main 2023 Solution View → 68

In an LC oscillator, if values of inductance and capacitance become twice and eight times, respectively, then the resonant frequency of oscillator becomes x times its initial reson

JEE Main 2023 Solution View → 69

An LCR series circuit of capacitance 62 . 5 nF and resistance of 50 Ω , is connected to an A.C. source of frequency 2 . 0 kHz . For maximum value of amplitude of current in ci

JEE Main 2023 Solution View → 70

Three identical resistors with resistance R = 12 Ω and two identical inductors with sell inductance L = 5 mH are connected to an ideal battery with emf of 12 V as shown in fig

JEE Main 2023 Solution View → 71

In the circuit shown in the figure, the ratio of the quality factor and the band width is _____ s .

JEE Main 2023 Solution View → 72

Consider an LC circuit, with inductance L = 0 . 1 H and capacitance C = 10 - 3 F , kept on a plane. The area of the circuit is 1 m 2 . It is placed in a constant magnetic field of

JEE Advanced 2022 Solution View → 73

A circuit element X when connected to an AC supply of peak voltage 100 V gives a peak current of 5 A which is in phase with the voltage. A second element Y when connected to the sa

JEE Main 2022 Solution View → 74

A capacitor of capacitance 500 μ F is charged completely using a de supply of 100 V . It is now connected to an inductor of inductance 50 mH to form an LC circuit. The maximum

JEE Main 2022 Solution View → 75

An alternating emf E = 440 sin 100 π t is applied to a circuit containing an inductance of 2 π H . If an a.c. ammeter is connected in the circuit, its reading will be :

JEE Main 2022 Solution View → 76

A coil of inductance 1 H and resistance 100 Ω is connected to a battery of 6 V . Determine approximately : (a) The time elapsed before the current acquires half of its steady-

JEE Main 2022 Solution View → 77

A transformer operating at primary voltage 8 kV and secondary voltage 160 V serves a load of 80 kW . Assuming the transformer to be ideal with purely resistive load and working on

JEE Main 2022 Solution View → 78

The equation of current in a purely inductive circuit is 5 sin 49 π t - 30 ° . If the inductance is 30 mH then the equation for the voltage across the inductor, will be

JEE Main 2022 Solution View → 79

The frequencies at which the current amplitude in an LCR series circuit becomes 1 2 times its maximum value, are 212 rad s - 1 and 232 rad s - 1 . The value of resistance in the ci

JEE Main 2022 Solution View → 80

A series LCR circuit has L = 0 . 01 H , R = 10 Ω and C = 1 μ F and it is connected to ac voltage of amplitude V m 50 V . At frequency 60 % lower than resonant frequency,

JEE Main 2022 Solution View → 81

A direct current of 4 A and an alternating current of peak value 4 A flow through resistance of 3 Ω and 2 Ω respectively. The ratio of heat produced in the two resistance

JEE Main 2022 Solution View → 82

To light, a 50 W , 100 V lamp is connected, in series with a capacitor of capacitance 50 π x μ F , with 200 V , 50 Hz AC source. The value of x will be _____ .

JEE Main 2022 Solution View → 83

The effective current I in the given circuit at very high frequencies will be _____ A .

JEE Main 2022 Solution View → 84

When you walk through a metal detector carrying a metal object in your pocket, it raises an alarm. This phenomenon works on

JEE Main 2022 Solution View → 85

To increase the resonant frequency in series LCR circuit,

JEE Main 2022 Solution View → 86

The RMS value of conduction current in a parallel plate capacitor is 6 . 9 μ A . The capacity of this capacitor, if it is connected to 230 V AC supply with an angular frequenc

JEE Main 2022 Solution View → 87

An inductor of 0 . 5 mH , a capacitor of 200 μF and a resistor of 2 Ω are connected in series with a 220 V ac source. If the current is in phase with the emf, the frequen

JEE Main 2022 Solution View → 88

For a series L C R circuit, I vs ω curve is shown (a) To the left of ω r , the circuit is mainly capacitive. (b) To the left of ω r , the circuit is mainly inductive

JEE Main 2022 Solution View → 89

In the given circuit, the magnitude of V L and V C are twice that of V R . Given that f = 50 Hz , the inductance of the coil is 1 K π mH . The value of K is _____ .

JEE Main 2022 Solution View → 90

An AC source is connected to an inductance of 100 mH , a capacitance of 100 μ F and a resistance of 120 Ω as shown in figure. The time in which the resistance having a th

JEE Main 2022 Solution View → 91

A telegraph line of length 100   km has a capacity of 0 . 01   μ F   km - 1 and it carries an alternating current at 0 . 5 kilo cycle per second. If minimum imp

JEE Main 2022 Solution View → 92

The current flowing through an ac circuit is given by I = 5 sin 120 π t A . How long will the current take to reach the peak value starting from zero?

JEE Main 2022 Solution View → 93

A 110 V , 50 Hz , AC source is connected in the circuit (as shown in figure). The current through the resistance 55 Ω , at resonance in the circuit, will be _____ A .

JEE Main 2022 Solution View → 94

A sinusoidal voltage V t = 210 sin 3000 t volt is applied to a series LCR circuit in which L = 10 mH , C = 25 μF and R = 100 Ω . The phase difference Φ between the a

JEE Main 2022 Solution View → 95

In a series LCR circuit, the inductance, capacitance and resistance are L = 100 mH , C = 100 μ F and R = 10 Ω respectively. They are connected to an AC source of voltage

JEE Main 2022 Solution View → 96

Match List - I with List - II. List-I List-II (A) AC generator (I) Detects the presence of current in the circuit (B) Galvanometer (II) Converts mechanical energy into electrical e

JEE Main 2022 Solution View → 97

If wattless current flows in the AC circuit, then the circuit is :

JEE Main 2022 Solution View → 98

Given below are two statements : Statement-I: The reactance of an ac circuit is zero. It is possible that the circuit contains a capacitor and an inductor. Statement-II: In ac circ

JEE Main 2022 Solution View → 99

A resistance of 40 Ω is connected to a source of alternating current rated 220 V , 50 Hz . Find the time taken by the current to change from its maximum value to the rms value

JEE Main 2022 Solution View → 100

As shown in the figure an inductor of inductance 200 mH is connected to an AC source of emf 220 V and frequency 50 Hz . The instantaneous voltage of the source is 0 V when the peak

JEE Main 2022 Solution View → 101

In a circuit, a metal filament lamp is connected in series with a capacitor of capacitance C F across a 200 ~V , 50 ~Hz supply. The power consumed by the lamp is 500 ~W while the v

JEE Advanced 2021 Solution View → 102

In a circuit, a metal filament lamp is connected in series with a capacitor of capacitance C F across a 200 ~V , 50 ~Hz supply. The power consumed by the lamp is 500 ~W while the v

JEE Advanced 2021 Solution View → 103

At very high frequencies, the effective impedance of the given circuit will be _________ Ω .

JEE Main 2021 Solution View → 104

In an ac circuit, an inductor, a capacitor and a resistor are connected in series with X L = R = X C . Impedance of this circuit is :

JEE Main 2021 Solution View → 105

An AC circuit has an inductor and a resistor of resistance R in series, such that X L = 3 R . Now, a capacitor is added in series such that X C = 2 R . the ratio of the new power f

JEE Main 2021 Solution View → 106

The alternating current is given by, i = 42 sin 2 π T t + 10 A . The R.M.S. value of this current is __________ A .

JEE Main 2021 Solution View → 107

In the given circuit the AC source has ω = 100 rad s - 1 . Considering the inductor and capacitor to be ideal, what will be the current I flowing through the circuit?

JEE Main 2021 Solution View → 108

A series LCR circuit driven by 300 V at a frequency of 50 Hz contains a resistance R = 3 kΩ , an inductor of inductive reactance X L = 250 π Ω and an unknown capacit

JEE Main 2021 Solution View → 109

An inductor coil stores 64 J of magnetic field energy and dissipates energy at the rate of 640 W when a current of 8 A is passed through it. If this coil is joined across an ideal

JEE Main 2021 Solution View → 110

A 100 Ω resistance, a 0 . 1 μ F capacitor and an inductor are connected in series across a 250 V supply at variable frequency. Calculate the value of inductance of induct

JEE Main 2021 Solution View → 111

A 0 . 07 H inductor and a 12 Ω resistor are connected in series to a 220 V , 50 Hz AC source. The approximate current in the circuit and the phase angle between current and so

JEE Main 2021 Solution View → 112

A 10 Ω resistance is connected across 220 V - 50 Hz AC supply. The time taken by the current to change from its maximum value to the rms value is:

JEE Main 2021 Solution View → 113

Two circuits are shown in figure ( a ) and ( b ) . At a frequency of _______ rad s - 1 the average power dissipated in one cycle will be the same in both the circuits.

JEE Main 2021 Solution View → 114

An inductor of 10 mH is connected to a 20 V battery through a resistor of 10 kΩ and a switch. After a long time, when maximum current is set up in the circuit, the current is

JEE Main 2021 Solution View → 115

In a circuit consisting of a capacitance and a generator with alternating emf, E g = E g o s i n ω t , V C and I C are the voltage and current. Correct phasor diagram for such

JEE Main 2021 Solution View → 116

Match List-I with List-II. List - I List - II (a) ω L > 1 ω C (i) Current is in phase with emf (b) ω L = 1 ω C (ii) Current lags behind the applied emf (c)

JEE Main 2021 Solution View → 117

For a series LCR circuit with R = 100 Ω , L = 0 . 5 mH and C = 0 . 1 pF connected across 220 V - 50 Hz AC supply, the phase angle between current and supplied voltage and the

JEE Main 2021 Solution View → 118

A series LCR circuit of R = 5 Ω , L = 20 mH and C = 0 . 5 μ F is connected across an AC supply of 250 V , having variable frequency. The power dissipated at resonance con

JEE Main 2021 Solution View → 119

A C voltage V ( t ) = 20 sin ω t of frequency 50 Hz is applied to a parallel plate capacitor. The separation between the plates is 2 mm and the area is 1 m 2 . The amplitude o

JEE Main 2021 Solution View → 120

In an L C R series circuit, an inductor 30 mH and a resistor 1 Ω are connected to an AC source of angular frequency 300 rad s - 1 . The value of capacitance for which the curr

JEE Main 2021 Solution View →
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