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. \( \frac{\mathrm{V}^2}{\mathrm{C} \omega} \)
A coil of \(40\) H inductance is connected in series with a resistance of \(8~\Omega\) and the combination is joined to the terminals of a \(2~\text{V}\) battery. The time constant of the circuit is:
1. \(1/5~\text{s}\)
2. \(40~\text{s}\)
3. \(20~\text{s}\)
4. \(5~\text{s}\)
Turn ratio of a step-up transformer is \(1: 25\). If current in load coil is \(2~\text{A}\), then the current in primary coil will be:
1. | \(25~\text{A}\) | 2. | \(50~\text{A}\) |
3. | \(0.25~\text{A}\) | 4. | \(0.5~\text{A}\) |
In a circuit \(L\), \(C\), and \(R\) are connected in series with an alternating voltage source of frequency \(f\). The current leads the voltage by \(45^\circ\). The value of \(C\) is:
1. \(\frac{1}{2 \pi f(2 \pi f L-R)}\)
2. \(\frac{1}{2\pi f(2 \pi f L+R)}\)
3. \(\frac{1}{ \pi f(2 \pi f L-R)}\)
4. \(\frac{1}{\pi f(2 \pi f L+R)}\)
The value of the quality factor is:
1.
2.
3.
4. L/R