- 1(current)
Q. No.
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. | \(\dfrac{\sqrt{3}}{2}\) |
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. \( 1.13 ~\text{W}\)
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 \(1000~\text{W}\). |
| 1. | (a) only |
| 2. | (b), (c) |
| 3. | (b), (d) |
| 4. | (a), (d) |
| 1. | resistive circuit | 2. | \({LC}\) circuit |
| 3. | inductive circuit | 4. | capacitive circuit |
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. | \(-{V_mI_m}\mathrm{sin}^{2}(\omega t)\) |
\(i=\frac{1}{\sqrt{2}}\sin\left(100\pi t \right )~\text{Ampere}\)
\(e=\frac{1}{\sqrt{2}}\sin\left(100\pi t+\pi /3 \right)~\text{Volt}\)
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. | \( \frac{1}{4}\) |
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. \( \frac{\mathrm{V}^2}{\mathrm{C} \omega} \)
- 1(current)
Q. No.
© 2025 GoodEd Technologies Pvt. Ltd.