Alternating Current · Physics · WB JEE
MCQ (Single Correct Answer)
1
In a series LCR circuit, the rms voltage across the resistor and the capacitor are $$30 \mathrm{~V}$$ and $$90 \mathrm{~V}$$ respectively. If the applied voltage is $$50 \sqrt{2} \sin \omega t$$, then the peak voltage across the inductor is
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2
When an AC source of emf E with frequency $$\omega$$ = 100 Hz is connected across a circuit, the phase difference between E and current I in the circuit is observed to be $${\pi \over 4}$$ as shown in the figure. If the circuit consist of only RC or RL in series, then
WB JEE 2022
3
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The rms value of potential difference V shown in the figure is
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4
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Consider a pure inductive AC circuit as shown in the figure. If the average power consumed is P, then
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5
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When a DC voltage is applied at the two ends of a circuit kept in a closed box, it is observed that the current gradually increases from zero to a certain value and then remains constant. What do you think that the circuit contains?
WB JEE 2020
6
When a 60 mH inductor and a resistor are connected in series with an AC voltage source, the voltage leads the current by 60$$^\circ$$. If the inductor is replaced by a 0.5 $$\mu$$F capacitor, the voltage lags behind the current by 30$$^\circ$$. What is the frequency of the AC supply?
WB JEE 2019
7
A parallel plate capacitor in series with a resistance of 100$$\Omega $$, an inductor of 20 mH and an AC voltage source of variable frequency shows resonance at a frequency of $${{1250} \over \pi }$$ Hz. If this capacitor is charged by a DC voltage source to a voltage 25 V, what amount of charge will be stored in each plate of the capacitor?
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8
An alternating current is flowing through a series L-C-R circuit. It is found that the current reaches a value of 1 mA at both 200 Hz and 800 Hz frequency. What is the resonance frequency of the circuit?
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9
When the frequency of the AC voltage applied to a series LCR circuit is gradually increased from a low value, the impedance of the circuit
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MCQ (More than One Correct Answer)
1
The variation of impedance $$\mathrm{Z}$$ of a series $$\mathrm{L C R}$$ circuit with frequency of the source is shown in the figure. Which of the following statement(s) is/are true ?
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2
A 400$$\Omega $$ resistor, a 250 mH inductor and a 2.5 $$\mu $$F capacitor are connected in series with an AC source of peak voltage 5 V and angular frequency 2kHZ. What is the peak value of the electrostatic energy of the capacitor?
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