1. | \(\frac{\sqrt{5} R}{2} ,\tan^{- 1} \left(2\right)\) | 2. | \(\frac{\sqrt{5} R}{2} , \tan^{- 1} \left(\frac{1}{2}\right)\) |
3. | \(\sqrt{5} X_{C} ,\tan^{- 1} \left(2\right)\) | 4. | \(\sqrt{5} R , \tan^{- 1} \left(\frac{1}{2}\right)\) |
In the adjoining ac circuit the voltmeter whose reading will be zero at resonance is
1. V1
2. V2
3. V3
4. V4
In the adjoining figure, the impedance of the circuit will be:
(1) 120 ohm
(2) 50 ohm
(3) 60 ohm
(4) 90 ohm
In a series \(LCR\) circuit, which one of the following curves represents the variation of impedance \((Z)\) with frequency \((f)\)?
1. | ![]() |
2. | ![]() |
3. | ![]() |
4. | ![]() |
The variation of the instantaneous current \((I)\) and the instantaneous emf \((E)\) in a circuit are shown in the figure. Which of the following statements is correct?
1. | The voltage lags behind the current by \(\frac{\pi}{2}\). |
2. | The voltage leads the current by \(\frac{\pi}{2}\). |
3. | The voltage and the current are in phase. |
4. | The voltage leads the current by \(\pi\). |
The figure shows the variation of R, XL, and XC with frequency f in a series L, C, R circuit. Then for what frequency point, the circuit is inductive:
1. A
2. B
3. C
4. All points
An ac source of variable frequency f is connected to an LCR series circuit. Which one of the graphs in the figure represents the variation of the current I in the circuit with frequency f :
1.
2.
3.
4.
The potential differences across the resistance, capacitance and inductance are \(80\) V, \(40\) V and \(100\) V respectively in an \(LCR\) circuit.
What is the power factor of this circuit?
1. \(0.4\)
2. \(0.5\)
3. \(0.8\)
4. \(1.0\)
An inductor 20 mH, a capacitor 50μF, and a resistor 40Ω are connected in series across a source of emf V=10sin340t. The power loss in the AC circuit is:
1. 0.67 W
2. 0.78W
3. 0.89 W
4. 0.46 W
A series R-C circuit is connected to an alternating voltage source. Consider two situations:
(1) When the capacitor is air-filled.
(2) When the capacitor is mica filled.
Current through the resistor is I and voltage across the capacitor is V then
1. Va<Vb
2. Va>Vb
3. ia>ib
4. Va=Vb