In a L-C-R circuit as shown below both switches are open initially. Now, switch S 1 and S 2 , are closed ( q is charge on the capacitor and τ = RC is capacitance time constant). Which of the following statement is correct?

Work done by the battery is half of the energy dissipated in the resistor

At t = τ/2, q = CV (1 – e-1)

JEE Questions for Physics Alternating Current Quiz 11

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70.7 V, 70.7 mA
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70.7 V, 70.7 A
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141.4 V, 141.4 mA
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141.4 V, 141.4 A
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100 V, 100 mA

If E₀ is the peak emf, I₀ is the peak current and ϕ is the phase difference between them, then the average power dissipation in the circuit is

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90°

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The instantaneous value of current in an AC circuit is I=2 sin (100 πt+π⁄3)A. The current will be maximum for the first time at.

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P = zero
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An L-C-R circuit contains R= 50 Ω, L = 1 mH and C = 0.1μF. The impedance of the circuit will be minimum for a frequency of

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In a L-C-R circuit as shown below both switches are open initially. Now, switch S₁ and S₂, are closed ( q is charge on the capacitor and τ = RC is capacitance time constant). Which of the following statement is correct?
Physics-Alternating Current-62337.png

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Work done by the battery is half of the energy dissipated in the resistor
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At t = τ, q = CV/2
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At t = 2τ, q = CV (1 – e-2)
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At t = τ/2, q = CV (1 – e-1)

In the circuit shown below what will be the readings of the voltmeter and ammeter? (Total impedance of circuit Z = 100Ω)
Physics-Alternating Current-62339.png

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200 V, 1 A
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800 V, 2 A
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100 V, 2 A
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220 V, 2.2 A

In the circuit shown in figure neglecting source resistance, the voltmeter and ammeter readings will be respectively
Physics-Alternating Current-62341.png

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0 V, 3 A
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150 V, 3 A
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150 V, 6 A
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0 V, 8 A

An inductor of inductance L = 400 mH and resistors of resistances R₁ = 4 Ω and R₂ = 2 Ω are connected to battery of emf 12 V as shown in the figure. The internal resistance of the battery is negligible. The switch S is closed at t = 0. The potential drop across L as a function of time is
Physics-Alternating Current-62343.png

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6e -5t V
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2)
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6(1 – e -t/0.V
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12e -5t V

In the given circuit diagram the current through the battery and the charge on the capacitor respectively in steady state are
Physics-Alternating Current-62346.png

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1 A and 3 μC
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17 A and 0 μC
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6/7 A and 12/7 μC
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6 A and 0 μC
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11 A and 3 μC

In an L-C-R series AC circuit the voltage across L, C and R is 10 V each. If the inductor is short circuited, the voltage across the capacitor would become

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10 V
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20 V

The natural frequency (ω₀) of oscillations in L -C circuit is given by

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From figure shown below a series L-C-R circuit connected to a variable frequency 200 V source. C = 80 μF and R = 40 Ω . Then the source frequency which drive the circuit at resonance is
Physics-Alternating Current-62362.png

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25 Hz
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50 Hz
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The impedance of a circuit, when a resistance R and an inductor of inductance L are connected in series in an AC circuit of frequency f, is

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For the series L-C-R circuit shown in the figure, what is the resonance frequency and the amplitude of the current at the resonating frequency?
Physics-Alternating Current-62377.png

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Let C be the capacitance of a capacitor discharging through a resistor R. Suppose t₁ is the time taken for the energy stored in the capacitor to reduce to half its initial value and t₂ is the time taken for the charge to reduce to one-fourth its ratio ti initial value.
Physics-Alternating Current-62384.png

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1
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2

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If the total charge stored in the LC circuit is Q₀, then for t ≥ 0

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A constant voltage at difference frequencies is applied across a capacitance C as shown in the figure. Which of the following graphs correctly depicts the variation of current with frequency
Physics-Alternating Current-62398.png

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The current T in an inductance coil varies with time \'e\' according to following graph
Which of the following plots shows the variation of voltage in the coil
Physics-Alternating Current-62404.png