AC Voltage Applied to a Series LCR Circuit

IMPORTANT

AC Voltage Applied to a Series LCR Circuit: Overview

This topic covers concepts such as Total Impedance in Series L-C-R Circuit, Variation of Impedance in Series AC Circuit with AC Frequency, Damped Oscillations in LCR Series Circuit, Series LCR Circuit, Phasor Diagrams for Series LCR Circuit, etc.

Important Questions on AC Voltage Applied to a Series LCR Circuit

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An a.c. voltage of 100 V, 50 Hz is connected across 20 Ω resistor and 2 mH inductor in series. What is the impedance of the circuit?

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When an inductor L and a resistor R in series are connected across a 12 V, 50 Hz supply a current of 0.5 A flows in the circuit. The current differs in phase from applied voltage by  π3 radian. The value of R is 

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What is damped and undamped oscillation?

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In RLC circuits, the circuit oscillates if _____ is zero.

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In damped oscillation of LCR series circuit charge amplitude is expressed as ( where qm=charge amplitude at t=0)

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In LCR series circuit amplitude of voltage across inductor is ( if Peak value of current=I0 and inductive reactance=XL=ωL)

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Assertion : In a series R, L, C circuit if VR, V1, and Vc denote r m s voltage across R, L and C respectively and Vs is the rms voltage across the source, then Vs=VR+VL+Vc.

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Reason:  Kirchoff voltage law is valid only for DC circuit, but it is not valid for AC circuit.

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What is the power factor of the circuit containing an inductor of inductance 1.5 H and a resistor of resistance 1500 Ω at a frequency of 1000 rad/s? Round it to one digit after the decimal point.

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What is the impedance of a series RLC circuit with resistance R=1354 Ω, capacitance C=2 μF and inductance L=2 H when the frequency of the source is 150 Hz. Round the answer to the nearest integer.

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A steady current of 2 A flows when an inductor of inductance 2mH is connected to ac source of emf 10 V. Now a capacitor of capacity 2μF is connected in series. If the current in the circuit is along the emf, the rms value of the current is

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For the ac circuit shown below, phase difference between emf and current is π4 radian as shown in the graph. If the impedance of the circuit is 1414 Ω then the values of P and Q are;

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In an LCR circuit, inductive reactance and capacitive reactance was found to be equal. The resistance was found to be 20 Ω. The probable impedance of the combination is

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A circuit containing a 80 mH inductor, and a 60 μF capacitor in series is connected to a 230 V50 Hz supply. The resistance of the circuit is negligible. Obtain the current amplitude.

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An applied voltage signal consists of a superposition of a dc voltage and an ac voltage of high frequency. The circuit consists of an inductor and a capacitor in series. Show that the dc signal will appear across C and the ac signal across L.

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The average power in a L-C-R circuit depends upon

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When 100 V DC. is applied across a coil, a current of 1 A flows through it. When 100 V AC. of frequency 50 Hz is applied to the same coil, only 0.5 A current flows through it. Calculate resistance, impedance and self inductance of the coil.

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Explain the term: Impedance.

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A series L-C-R circuit containing R=20 Ω, L=200 mH and C=40 μF is joined to a 120 V, 60 Hz AC source. Find (i) Total reactance (ii) impedance (iii) power factor (iv) average power.

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Write down the expression for impedance, frequency and power factor for a series L-C-R AC circuit?

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If fr is the resonant frequency of AC circuit. Give phase relationship between voltage and current for (i) f<fr (ii) f=fr (iii) f>fr