For the circuit shown in the figure, the time constant is
If i=2t, then the R.M.S. value of current between 0 to 2 second is
L, C, and R denote inductance, capacitance, and resistance respectively. pick out the combination which does not have the dimension of frequency.
The phase difference () between emf and current in LCR series a.c. circuit is
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