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Physics - Alternating Current

Practise 193 JEE Main previous year questions on Alternating Current, compiled from papers spanning 2002 to 2026. Each question is pulled directly from the actual exam paper it appeared in, so you're practising in the exact style and difficulty JEE Main tests.

Alternating Current has been asked in 23 of the 25 years of JEE Main papers analysed (2002–2026), with 193 questions in all. 34% of them were easy, 52% moderate and 15% tough. Most of its questions came from 2021, with 40 questions that year. In the last three years (2024–2026) it had 39 questions across 49 papers, about 0.8 per paper.

The chapter's 5 topics are not weighted equally: AC Circuits (109 questions, 56%), Alternating Current, Voltage and Power (48 questions, 25%), and Transformers (17 questions, 9%) have been asked the most. AC Circuits has also led over the last five years, with 51 questions. AC Circuits has produced the most tough questions (23).

  1. 1A LCR series circuit driven with V at frequency Hz has resistance , an inductance with inductive reactance and capacitance with capacitive r06 Apr, 2026 (M)AC Circuits
  2. 2An a.c. source of angular frequency is connected across a resistor and a capacitor in series. The current is observed as . Now the frequency05 Apr, 2026 (M)AC Circuits
  3. 3A series LCR circuit with , and is connected to a variable frequency a.c. source. The inductive reactance at resonant frequency is _______ .05 Apr, 2026 (E)AC Circuits
  4. 4An inductor of mH, capacitor of F and a resistor of are connected in series across an power supply V, Hz. The power factor of the given circ04 Apr, 2026 (M)AC Circuits
  5. 5The figure given below shows an series circuit with two switches and . When switch is closed keeping open, the phase difference between the 02 Apr, 2026 (E)AC Circuits
  6. 6The electric current in the circuit is given as . The r.m.s current for the period to is .28 Jan, 2026 (M)Alternating Current, Voltage and Power
  7. 7An 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 (rm28 Jan, 2026 (E)AC Circuits
  8. 8For the series circuit connected with a.c source as shown in the figure, the power factor is . The value of is .24 Jan, 2026 (M)Quality and Power Factor
  9. 9Using a variable frequency a.c. voltage source the maximum current measured in the given LCR circuit is 50 mA for The values of and are show23 Jan, 2026 (M)AC Circuits
  10. 10A capacitor is first charged fully with potential difference of and disconnected from the battery. The charged capacitor is connected across21 Jan, 2026 (E)AC Circuits
  11. 11An ac current is represented as The r.m.s value of the current is07 Apr, 2025 (M)Alternating Current, Voltage and Power
  12. 12For ac circuit shown in figure, and and the phase difference between and is . The input signal frequency is , where ' x ' is ______07 Apr, 2025 (M)AC Circuits
  13. 13An inductor of reactance , a capacitor of reactance , and a resistor of resistance are connected in series with an AC source of 10 V , 50 Hz07 Apr, 2025 (E)Alternating Current, Voltage and Power
  14. 14An alternating current is represented by the equation, ampere. The RMS value of current and the frequency of the given alternating current a04 Apr, 2025 (M)Alternating Current, Voltage and Power
  15. 15An inductor of self inductance 1 H connected in series with a resistor of and an ac supply of volt, 50 Hz. Maximum current flowing in the ci04 Apr, 2025 (E)Parallel AC Circuits
  16. 16An electric bulb rated as is connected to an ac source of rms voltage 220 V. The peak value of current through the bulb is :03 Apr, 2025 (E)Alternating Current, Voltage and Power
  17. 17Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Choke coil is sim29 Jan, 2025 (M)Alternating Current, Voltage and Power
  18. 18An alternating current is given by . The r.m.s current will be24 Jan, 2025 (M)Alternating Current, Voltage and Power
  19. 19In a series LCR circuit, a resistor of , a capacitor of 25 nF and an inductor of 100 mH are used. For maximum current in the circuit, the an23 Jan, 2025 (E)AC Circuits
  20. 20A series LCR circuit is connected to an alternating source of emf E. The current amplitude at resonant frequency is . If the value of resist22 Jan, 2025 (E)AC Circuits
  21. 21A capacitor of reactance and a resistor of resistance are connected in series with an ac source of peak value . The power dissipation in the09 Apr, 2024 (E)AC Circuits
  22. 22A LCR circuit is at resonance for a capacitor , inductance and resistance . Now the value of resistance is halved keeping all other paramete08 Apr, 2024 (M)AC Circuits
  23. 23A coil of negligible resistance is connected in series with resistor across supply. A voltmeter reads across resistance. Inductance of the c08 Apr, 2024 (E)AC Circuits
  24. 24An alternating emf volt is applied to a capacitor of , the rms value of current in the circuit is _____ ,08 Apr, 2024 (E)AC Circuits
  25. 25Given below are two statements: Statement I: In an LCR series circuit, current is maximum at resonance. Statement II: Current in a purely re06 Apr, 2024 (M)AC Circuits
  26. 26When a voltage of is applied to an inductor, a current of flows through it. When an ac voltage of peak value is connected to inductor, its i06 Apr, 2024 (M)AC Circuits
  27. 27For a given series LCR circuit it is found that maximum current is drawn when value of variable capacitance is . If resistance of and induct06 Apr, 2024 (E)AC Circuits
  28. 28An ac source is connected in given series LCR circuit. The rms potential difference across the capacitor of is _____V.05 Apr, 2024 (M)AC Circuits
  29. 29A series LCR circuit is subjected to an ac signal of . If the voltage across the inductor is , then the current in this circuit is _____ .05 Apr, 2024 (E)AC Circuits
  30. 30In an ac circuit, the instantaneous current is zero, when the instantaneous voltage is maximum. In this case, the source may be connected to04 Apr, 2024 (M)Alternating Current, Voltage and Power
  31. 31A alternating current at any instant is given by A. The value of the current is ________ A.04 Apr, 2024 (M)Alternating Current, Voltage and Power
  32. 32Match List I with List II04 Apr, 2024 (E)AC Circuits
  33. 33A 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 r01 Feb, 2024 (M)Alternating Current, Voltage and Power
  34. 34In series LCR circuit, the capacitance is changed from C to 4 C . To keep the resonance frequency unchanged, the new inductance should be :01 Feb, 2024 (M)AC Circuits
  35. 35A 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 c01 Feb, 2024 (E)Transformers
  36. 36An 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 diss31 Jan, 2024 (E)Alternating Current, Voltage and Power
  37. 37A 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 = 30 Jan, 2024 (M)Quality and Power Factor
  38. 38Primary coil of a transformer is connected to 220 V A C . Primary and secondary turns of the transforms are 100 and 10 respectively. Seconda30 Jan, 2024 (M)Transformers
  39. 39An 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 rise30 Jan, 2024 (E)Alternating Current, Voltage and Power
  40. 40A power transmission line feeds input power at 2 . 3 kV to a step down transformer with its primary winding having 3000 turns . The output p30 Jan, 2024 (E)Transformers
  41. 41In 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 power29 Jan, 2024 (E)Alternating Current, Voltage and Power
  42. 42In 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 .29 Jan, 2024 (E)AC Circuits
  43. 43A 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 f27 Jan, 2024 (E)Quality and Power Factor
  44. 44The 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 resi27 Jan, 2024 (E)Transformers
  45. 45Given below are two statements: Statement I : An AC circuit undergoes electrical resonance if it contains either a capacitor or an inductor.13 Apr, 2023 (E)AC Circuits
  46. 46Given below are two statements: Statement I : When the frequency of an AC source in a series LCR circuit increases, the current in the circu12 Apr, 2023 (M)AC Circuits
  47. 47As per the given graph, choose the correct representation for curve A and curve B {Where X C = Reactance of pure capacitive circuit connecte11 Apr, 2023 (M)AC Circuits
  48. 48Given below are two statements: Statement I: Maximum power is dissipated in a circuit containing an inductor, a capacitor and a resistor con10 Apr, 2023 (M)AC Circuits
  49. 49An oscillating LC circuit consists of a 75 mH inductor and a 1 . 2 F capacitor. If the maximum charge to the capacitor is 2 . 7 C . The maxi08 Apr, 2023 (M)AC Circuits
  50. 50A series combination of resistor of resistance 100 inductor of inductance 1 H and capacitor of capacitance 6 . 25 F is connected to an ac so08 Apr, 2023 (E)Quality and Power Factor

Frequently Asked Questions

1.How many questions are available for Alternating Current?

This chapter includes 193 questions compiled from JEE Main papers spanning 2002 to 2026.

2.Are these questions only from JEE Main, or from other exams too?

These are JEE Main questions specifically for the Alternating Current chapter. Questions from other exams like NTA Abhyas (JEE Main) or JEE Advanced are organised separately under their respective exam sections.

3.Is Alternating Current an important chapter for JEE Main Physics?

Alternating Current has appeared in 23 of the 25 years of JEE Main papers covered here, with 193 questions across 140 papers - about one per paper it appears in.

4.What is the difficulty level of Alternating Current questions in JEE Main?

Of the 193 questions analysed for this chapter, 34% are easy, 52% moderate and 15% tough. 2021 had the most, with 40 questions.

5.Which topics in Alternating Current should I focus on?

These topics have carried the most weightage in Alternating Current:

  • AC Circuits - 109 questions (56%)
  • Alternating Current, Voltage and Power - 48 questions (25%)
  • Transformers - 17 questions (9%)
  • AC Circuits has produced the most tough questions (23).
6.Is Alternating Current's weightage in JEE Main going up or down?

Across all 140 papers analysed, Alternating Current has averaged about 1.4 questions per paper. In the last three years (2024–2026), that average has fallen, at about 0.8 questions per paper. Use the year-wise numbers on this page for the exact trend before you decide how much time to give it.