A \(50\) Hz AC source of \(20\) volts is connected across \(R\) and \(C\) as shown in the figure below.
If the voltage across \(R\) is \(12\) volts, then the voltage across \(C\) will be:
1. | \(8\) V |
2. | \(16\) V |
3. | \(10\) V |
4. | not possible to determine unless values of \(R\) and \(C\) are given |
In an ideal parallel LC circuit, the capacitor is charged by connecting it to a dc source which is then disconnected. The current in the circuit will:
1. Become zero instantaneously.
2. Grow monotonically.
3. Decay monotonically.
4. Oscillate instantaneously.
1. | \(10\) mH |
2. | \(100\) mH |
3. | \(1\) mH |
4. | Cannot be calculated unless \(R\) is known |
1. | AC cannot pass through DC Ammeter. |
2. | AC changes direction. |
3. | Average value of current for the complete cycle is zero. |
4. | DC Ammeter will get damaged. |
1. | \(\dfrac{E^2_0}{\sqrt{2}R}\) | 2. | \(\dfrac{E^2_0}{4R}\) |
3. | \(\dfrac{E^2_0}{2R}\) | 4. | \(\dfrac{E^2_0}{8R}\) |
A series AC circuit has a resistance of \(4~\Omega\) and an inductor of reactance \(3~\Omega\). The impedance of the circuit is \(z_1\). Now when a capacitor of reactance \(6~\Omega\) is connected in series with the above combination, the impedance becomes \(z_2\). Then \(\frac{z_1}{z_2}\) will be:
1. \(1:1\)
2. \(5:4\)
3. \(4:5\)
4. \(2:1\)
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 inductor \((L)\) and resistance \((R)\) are connected in series with an AC source. The phase difference between voltage \((V)\) and current \((i)\) is \(45^{\circ}.\)
If the phase difference between \(V\) and \(i\) remains the same, then the capacitive reactance and impedance of the \(LCR\) circuit will be:
1. \(2R, R\sqrt{2}\)
2. \(R, R\sqrt{2}\)
3. \(R, R\)
4. \(2R, R\sqrt{3}\)
The core of a transformer is laminated because:
1. | Energy losses due to eddy currents may be minimized |
2. | The weight of the transformer may be reduced |
3. | Rusting of the core may be prevented |
4. | Ratio of voltage in primary and secondary may be increased |