The primary and secondary coils of an ideal transformer have 100 and 5000 turns respectively. The magnetic flux linking the primary coil is given by = 20t + 10. The output voltage across the secondary coil is
1. 20 V
2. 500 V
3. 1000 V
4. 10000 V
In the LCR-circuit shown below, if the reading of the voltmeters and are same, then
1.
2. Reading of the voltmeter V is 50 V
3. Reading of the ammeter A is 5 A
4. All of these
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
Which of the following is/are copper loss/losses in a transformer?
1. Hysteresis loss
2. Eddy current loss
3. Heat loss in the primary and second coils
4. Both (1) & (2)
Half power frequencies for the circuit shown below are 200rad/s and 800 rad/s. The value of the product LC is
In the network shown below what is the reading of the a.c voltmeter?
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)
The variation of alternating current (l) with time (t) is shown in the given graph. The average value of current for half cycle is:
A capacitor and a resistor are connected in series across a.c. supply. Which of the following phasor diagram may be correct?
1.
2.
3.
4.