NEET PhysicsNCERT Class 12Electromagnetic Induction and Alternating Currents

Alternating Current: NEET questions with solutions

NEET tests rms and peak values, reactances XL = ωL and XC = 1/ωC, impedance and phase in a series LCR circuit, resonance, average power VI cos φ and the power factor, and ideal transformer ratios. Marks are lost by adding the voltages across R, L and C as plain numbers, by mixing peak and rms values, by using f where ω is needed, and by keeping current rather than power the same across a transformer.

Revise first: NCERT notes for Alternating Current

Questions

10 questions · answers after you pick

1An ac supply has instantaneous voltage v = 311 sin(314t) volts, with t in seconds. What are its rms voltage and frequency?RMS values and average powerEasySingle correct 2What is the reactance of a 10 μF capacitor connected to a 50 Hz ac supply?AC through a capacitorEasySingle correct 3A series LCR circuit has R = 30 Ω, X_L = 80 Ω and X_C = 40 Ω, and is connected to a 100 V (rms) ac supply. What is the rms current?Series LCR circuit and impedanceMediumSingle correct 4A series LCR circuit contains an inductor of 0.40 H and a capacitor of 25 μF. At what frequency of the source does resonance occur?ResonanceMediumSingle correct 5An ideal inductor (no resistance) is connected across an ac source. Read the Assertion (A) and Reason (R) and choose the correct option.AC through an inductorMediumAssertion–Reason 6A series LCR circuit with R = 40 Ω, X_L = 60 Ω and X_C = 30 Ω is connected to a 200 V (rms) ac supply. What average power does it draw?Power factorMediumSingle correct 7A series LCR circuit with R = 100 Ω is at resonance at frequency f₀, where X_L = X_C = 100 Ω. The source frequency is now doubled to 2f₀…ResonanceHardSingle correct 8An ideal transformer (no energy losses) has 100 turns on its primary coil and 2000 turns on its secondary coil. The primary is connected to…TransformersMediumSingle correct 9Consider the following statements about ac circuits with a single ideal element. Which of them are correct?PhasorsEasyStatement based 10A coil draws 4.0 A when connected to a 12 V dc source. When the same coil is connected to a 12 V (rms), 50 Hz ac source, it draws 2.4 A…Series LCR circuit and impedanceHardSingle correct

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