Turn ratio of a step-up transformer is 1 : 25. If current in load coil is 2 A,
then the current in primary coil will be:
1. 25 A
2. 50 A
3. 0.25 A
4. 0.5 A
The value of the quality factor is:
1.
2.
3.
4. L/R
A capacitor of capacity C has reactance X. If capacitance and frequency are doubled, then the reactance will be:
1. 4X
2.
3.
4. 2X
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 V battery. The time constant of the circuit is:
1. 1/5 s
2. 40 s
3. 20 s
4. 5 s
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. \(\frac{1}{2 \pi f(2 \pi f L+R)}\)