To an AC power supply of 220 V at 50 Hz, a resistor of 20 Ω, a capacitor of reactance 25 Ω and an in

Q: What is NEET?

NEET is a competitive examination conducted in India. This question is from the 2025 NEET Physics paper.

Q: How can I prepare for NEET Physics?

To prepare for NEET Physics, practice previous year questions (PYQs), understand concepts thoroughly, and solve mock tests regularly. This 2025 question covers Alternating Current topic.

Q: What is the difficulty level of this question?

This NEET 2025 Physics question has a medium difficulty level and is marked as an important question and is one of the most repeated questions.

Q: Where can I find more NEET previous year questions?

You can find more NEET previous year questions on AspirantMitraa. Browse by subject, topic, year, and difficulty level to practice effectively.

Question

To an AC power supply of 220 V at 50 Hz, a resistor of 20 Ω, a capacitor of reactance 25 Ω and an inductor of reactance 45 Ω are connected in series. The corresponding current in the circuit and the phase angle between the current and voltage respectively are:

Accepted Answer

Correct Answer: C — 7.8 A and 45°Step-by-step Solution:Given: Vrms = 220 V, R = 20 Ω, XL = 45 Ω, XC = 25 ΩImpedance:Z = √(R² + (XL − XC)²) = √(20² + (45 − 25)²) = √(400 + 400) = √800 = 20√2 ≈ 28.28 ΩCurrent:Irms = Vrms/Z = 220/(20√2) = 11/√2 ≈ 7.78 ≈ 7.8 APhase angle:tan φ = (XL − XC)/R = (45 − 25)/20 = 20/20 = 1φ = tan⁻¹(1) = 45°Since XL > XC, the circuit is inductive and voltage leads current by 45°.Why Option A (15.6 A and 45°) is wrong: Phase angle 45° is correct, but 15.6 A ≈ 220/14.14 — this arises from using Z = 14.14 Ω instead of 20√2 ≈ 28.28 Ω (perhaps halved in error).Why Option B (7.8 A and 30°) is wrong: Current 7.8 A is correct, but tan(30°) = 1/√3 ≈ 0.577, which would require (XL−XC)/R ≈ 0.577 — not the case here where it equals 1.Why Option D (15.6 A and 30°) is wrong: Both values are incorrect — combines the current error of A with the phase error of B.Key Concepts from Alternating Current (NCERT Class 12, Chapter 7):Impedance: Z = √(R² + (XL − XC)²). XL = ωL; XC = 1/(ωC).Phase angle: tan φ = (XL − XC)/R. If XL > XC: inductive circuit, voltage leads current. If XC > XL: capacitive, current leads voltage.Resonance: XL = XC, so Z = R (minimum). Current is maximum and in phase with voltage. f₀ = 1/(2π√LC).Power: P = VrmsIrms cosφ = I²R. Power factor = cosφ. Pure L or C: cosφ = 0 (no power dissipated).Q-factor: Q = (1/R)√(L/C) = ω₀L/R. Higher Q → sharper resonance.

To an AC power supply of 220 V at 50 Hz, a resistor of 20 Ω, a capacitor of reactance 25 Ω and an inductor of reactance 45 Ω are connected in series. The corresponding current in the circuit and the phase angle between the current and voltage respectively are:

Master NEET with Our Test Series

More Questions from Alternating Current

Frequently Asked Questions

To an AC power supply of 220 V at 50 Hz, a resistor of 20 Ω, a capacitor of reactance 25 Ω and an inductor of reactance 45 Ω are connected in series. The corresponding current in the circuit and the phase angle between the current and voltage respectively are:

Master NEET with Our Test Series

More Questions from Alternating Current

Frequently Asked Questions