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. | \(0\) |
In LC oscillation, what is the current in the circuit when the total energy is stored in the form of magnetic energy?
(q0 is the maximum charge stored by the capacitor)
1. | zero | 2. | \(\dfrac{1}{2}\) |
3. | \(\dfrac{1}{\sqrt{2}}\) | 4. | \(1\) |
1. | \(\dfrac{E_{0}^{2}}{R} \sin^{2}\omega t\) | 2. | \(\dfrac{E_{0}^{2}}{R}\cos^{2}\omega t\) |
3. | \(\dfrac{E_{0}^{2}}{R}\) | 4. | \(\text{zero}\) |
In a step-up transformer, the turn ratio is \(1:20\). The resistance of \(100~\Omega\) connected across the secondary is drawing a current of \(2~\text{A}\).
What are the primary voltage and current respectively?
1. \(100~\text{V}, 0.5~\text{A}\)
2. \(200~\text{V},10~\text{A}\)
3. \(10~\text{V}, 40~\text{A}\)
4. \(10~\text{V}, 20~\text{A}\)