The primary winding of a transformer has 500 turns whereas its secondary has 5000 turns. The primary is connected to an ac supply of 20 V, 50 Hz. What will be the output of the secondary transformer?

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

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:
           

The power factor of a series LCR circuit in resonance condition is:

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

What is the instantaneous power of a resistor having resistance R across an ac supply of E=E₀sin ωt?

$1.$ $\frac{{E_0}^2}{R}{\sin }^2$ $\omega t$
$2.$ $\frac{{E_0}^2}{R}{\cos }^2$ $\omega t$
$3.$ $\frac{{E_0}^2}{R}$
$4.$ $zero$ $$

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 A. What are the primary voltage and current respectively?

1. 100 V, 0.5 A

2. 200 V, 10 A

3. 10 V, 40 A

4. 10 v, 20 A

Voltage and current in an ac circuit are given by \(V=5sin\left ( 100\pi t-\frac{\pi }{6}~ \right )~V\) and \(I=4sin\left ( 100\pi t+\frac{\pi }{6}~ \right )~A.\)
Hence:

An alternating voltage (in volts) given by \(V=200\sqrt{2}sin100t\) is connected to a\(1~\mu F\) capacitor through an \(ac\) ammeter. The reading of the ammeter will be:

It is found that the current through the LCR series circuit is at its maximum. If $V_r,V_c\mathrm{ a}nd{\mathrm{ V}}_L$ are potential differences across resistance, capacitor, and inductor respectively, then which of the following is correct?