In an electrical circuit \(R,\) \(L,\) \(C\) and an AC voltage source are all connected in series. When \(L\) is removed from the circuit, the phase difference between the voltage and the current in the circuit is \(\tan^{-1}\sqrt{3}\). If instead, \(C\) is removed from the circuit, the phase difference is again \(\tan^{-1}\sqrt{3}\). The power factor of the circuit is:

1. \(\dfrac{1}{2} \) 2. \(\dfrac{1}{\sqrt{2}}\)
3. \(1 \) 4. \(\dfrac{\sqrt{3}}{2}\)

Subtopic:  Power factor |
 82%
Level 1: 80%+
AIPMT - 2012
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An inductor of \(20~\text{mH}\), a capacitor of \(100~\mu \text{F}\), and a resistor of \(50~\Omega\) are connected in series across a source of emf, \(V=10 \sin (314 t)\). What is the power loss in this circuit?
1. \( 0.79 ~\text{W} \)
2. \( 0.43 ~\text{W} \)
3. \( 2.74 ~\text{W} \)
4. \( 1.13 ~\text{W}\)

Subtopic:  Power factor |
 55%
Level 3: 35%-60%
NEET - 2018
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An AC source rated \(100~\text{V}\) (rms) supplies a current of \(10~\text{A}\) (rms) to a circuit. The average power delivered by the source:

(a) must be \(1000~\text{W}\).
(b) may be \(1000~\text{W}\).
(c) may be greater than \(1000~\text{W}\).
(d) may be less than \(1000~\text{W}\).
Choose the correct option:
1. (a) only
2. (b), (c)
3. (b), (d)
4. (a), (d)

Subtopic:  Power factor |
 64%
Level 2: 60%+
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The maximum power is dissipated for an AC in a/an:
1. resistive circuit 2. \({LC}\) circuit
3. inductive circuit 4. capacitive circuit
Subtopic:  Power factor |
 75%
Level 2: 60%+
NEET - 2023
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An AC source given by \(V=V_m\sin(\omega t)\) is connected to a pure inductor \(L\) in a circuit and \(I_m\) is the peak value of the AC current. The instantaneous power supplied to the inductor is:

1. \(\dfrac{V_mI_m}{2}\mathrm{sin}(2\omega t)\) 2. \(-\dfrac{V_mI_m}{2}\mathrm{sin}(2\omega t)\)
3. \({V_mI_m}\mathrm{sin}^{2}(\omega t)\) 4. \(-{V_mI_m}\mathrm{sin}^{2}(\omega t)\)
Subtopic:  Power factor |
Level 3: 35%-60%
NEET - 2022
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The instantaneous values of alternating current and voltages in a circuit are given as,
\(i=\frac{1}{\sqrt{2}}\sin\left(100\pi t \right )~\text{Ampere}\)
\(e=\frac{1}{\sqrt{2}}\sin\left(100\pi t+\pi /3 \right)~\text{Volt}\)
What is the average power consumed by the circuit in watts?
1. \( \frac{\sqrt{3}}{4} \) 2. \( \frac{1}{2} \)
3. \( \frac{1}{8} \) 4. \( \frac{1}{4}\)
Subtopic:  Power factor |
 76%
Level 2: 60%+
AIPMT - 2012
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For a series \(\mathrm{LCR}\) circuit, the power loss at resonance is:
1. \(\frac{V^2}{\left[\omega L-\frac{1}{\omega C}\right]}\)

2. \( \mathrm{I}^2 \mathrm{~L} \omega \)

3. \(I^2 R\)

4. \( \frac{\mathrm{V}^2}{\mathrm{C} \omega} \)

Subtopic:  Power factor |
 81%
Level 1: 80%+
AIPMT - 2002
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