In the LCR-circuit shown below, if the reading of the voltmeters $V_{1 }$and $V_2$ are same, then

     

1. ${\omega }^2=\frac{1}{LC}$

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 $(is secon{d}^2/radia{n}^2)$

$1. 6.25 \times {10}^{-3}$
$2. 6.25\times {10}^{-6}$
$3. 1.25\times {10}^{-3}$
$4. 1.25\times {10}^{-5}$

The power factor of the given circuit is:
             

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)

$1.$ $Zero$ $$
$2.$ $\frac{q_0}{\sqrt{Lc}}$ $$
$3.$ $\frac{q_0}{LC}$ $$
$4.$ $q_0\sqrt{LC}$

The variation of alternating current (l) with time (t) is shown in the given graph. The average value of current for half cycle is:
         

$1. \frac{2{/}_0}{\pi }$
$2. \frac{l_0}{\sqrt{2}}$
$3. \frac{l_0}{2}$
$4. Zero$

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.

An inductor of inductance (L), a capacitor of capacitance (C), and a resistor of resistance (R) are connected in series across $E=E_0\sin \frac{t}{\sqrt{LC}}$, The reading of hot wire voltmeter connected across the resistor is

$1. E_0$
$2. \frac{E_0}{\sqrt{2}}$
$3. \frac{E_0}{2}$
$4. zero$