Alternating Current is a Class 12 Physics chapter that carries about 3.9% of the Physics questions in NEET. Practise it with 44 questions covering 2 topics, each with an explanation.
Sets of 15 questions that adapt to your level, with an explanation for every answer.
Across the 13 previous year papers, Alternating Current had 22 questions, about 1.7 a year. The most in one paper was 4, in NEET 2023.
| Paper | Questions from this chapter |
|---|---|
| NEET 2026 | 2 |
| NEET 2025 | 1 |
| NEET 2024 | 2 |
| NEET 2023 | 4 |
| NEET 2022 | 3 |
| NEET 2021 | 3 |
| NEET 2020 | 2 |
| NEET 2019 | 0 |
| NEET 2018 | 1 |
| NEET 2017 | 0 |
| NEET 2016 | 2 |
| Re-AIPMT 2015 | 1 |
| AIPMT 2014 | 1 |
8 questions from the practice bank, spread across the chapter's topics. The full set is in the app.
At resonance in a series LCR circuit, the impedance of the circuit is:
Answer: B. minimum, equal to R
Why: At resonance, XL and XC cancel each other, so the impedance Z=√(R²+(XL-XC)²) reduces to its minimum value, equal to R alone.
The average power consumed in an AC circuit is given by:
Answer: B. V_rms I_rms cos φ
Why: cos φ is the power factor.
A choke coil is used in AC circuits instead of a resistor to limit the current because it:
Answer: B. reduces the current with almost no loss of power
Why: The current lags the voltage by nearly 90°, so the average power is small.
A transformer works on the principle of:
Answer: A. mutual induction
Why: A transformer operates on the principle of mutual electromagnetic induction — a changing current in the primary coil induces an EMF in the secondary coil via the shared magnetic flux.
In a step-down transformer, compared with the primary, the secondary has:
Answer: C. lower voltage and higher current
Why: Power is nearly conserved, so V_pI_p ≈ V_sI_s.
In a purely inductive AC circuit the current:
Answer: C. lags the voltage by 90°
Why: The induced emf opposes changes in current, so the current reaches its maximum a quarter-cycle after the voltage.
In an LC circuit, the energy:
Answer: B. oscillates between the electric field of the capacitor and the magnetic field of the inductor
Why: The oscillation frequency is 1/(2π√LC), and without resistance it would continue for ever.
The average value of AC over half a cycle, I = I₀ sin ωt, is:
Answer: C. 2I₀/π, about 0.637 I₀
Why: The full-cycle average is zero, but half a cycle has the average 2I₀/π.
Alternating Current carries about 3.9% of the Physics questions in NEET. Across the 13 previous year papers on NeetVictory it appeared 22 times, about 1.7 questions a year.
Alternating Current is a Class 12 Physics chapter in the NCERT syllabus.
NeetVictory has 44 practice questions on Alternating Current, each with an explanation, in sets of 15 that adapt to your level. This page shows a free sample.
NeetVictory