The power factor of the given circuit is:
           

1.	\(1 \over 2\)	2.	\(1 \over \sqrt2\)
3.	\(\sqrt3 \over 2\)	4.	\(0\)

$\mathrm{}$

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?

In a series LCR circuit, the current through the ac source is 2 A. If resistor R has a resistance of 10 Ω, the average power dissipated in the circuit is:

1. 20 W

2. 30 W

3. 10 W

4. 40 W

A capacitor of capacitance 1 $\mu F$ is charged to a potential of 1 V. It is connected in parallel to an inductor of inductance ${10}^{-3}$H. What is the value of the maximum current that will flow in the circuit?

$1.$ $\sqrt{1000}$ $mA$
$2.$ $1$ $mA$ $$
$3.$ $1$ $\mu F$
$4.$ $1000$ $mA$

In a box Z of unknown elements (L or R or any other combination), an ac voltage $E=E_0\sin (\omega t+\varphi )$ $$is applied and the current in the circuit is found to be $I=I_0\sin (\omega t+\varphi +\frac{\pi }{4})$. The unknown elements in the box could be: