An AC source of variable frequency \(f\) is connected to an \(LCR\) series circuit. Which of the following graphs represents the variation of the current \(I\) in the circuit with frequency \(f\)?
1. | ![]() |
2. | ![]() |
3. | ![]() |
4. | ![]() |
1. | \(0.67~\text{W}\) | 2. | \(0.78~\text{W}\) |
3. | \(0.89~\text{W}\) | 4. | \(0.46~\text{W}\) |
1. | \(5000\) | 2. | \(50\) |
3. | \(500\) | 4. | \(5\) |
Match List I (expression for current) with List II (rms value of current) and select the correct answer.
List I | List II | ||
(a) | \(I=I_0 \sin \omega t \cos \omega t\) | (i) | \(I_0\) |
(b) | \(I=I_0 \sin \left(\omega t+\frac{\pi}{3}\right)\) | (ii) | \(I_0/\sqrt{2}\) |
(c) | \(I_0(\sin \omega t+\cos \omega t)\) | (iii) | \(I_0e\) |
(d) | \(I=I_0(e)\) | (iv) | \(I_0/2\sqrt{2}\) |
A | B | C | D | |
1. | (iv) | (ii) | (i) | (iii) |
2. | (iv) | (ii) | (iii) | (i) |
3. | (ii) | (iv) | (iii) | (i) |
4. | (ii) | (iv) | (i) | (iii) |
1. | \(120\) V | 2. | \(220\) V |
3. | \(30\) V | 4. | \(90\) V |
1. | \(200\) V, \(50\) Hz |
2. | \(2\) V, \(50\) Hz |
3. | \(200\) V, \(500\) Hz |
4. | \(2\) V, \(5\) Hz |
If \(R\) and \(L\) are resistance and inductance of a choke coil and \(f\) is the frequency of current through it, then the average power of the choke coil is proportional to:
1. \(R ~\)
2. \(\frac{1}{f^2}\)
3. \(\frac{1}{L^2}\)
4. All of these
1. | Zero | 2. | \(100\) V |
3. | \(200\) V | 4. | \(500\) V |
The power factor of the given circuit is:
1. | \(1 \over 2\) | 2. | \(1 \over \sqrt2\) |
3. | \(\sqrt3 \over 2\) | 4. | \(0\) |
1. | zero | 2. | \(\dfrac{1}{2}\) |
3. | \(\dfrac{1}{\sqrt{2}}\) | 4. | \(1\) |