In an ac circuit, the current is given by \(i=5\sin(100t-\frac{\pi}{2})\) and the ac potential is V = 200 sin(100t) volt. The power consumption is:

1. 20 W

2. 40 W

3. 1000 W

4. 0 

A coil of inductive reactance of 31 Ω has a resistance of 8 Ω. It is placed in series with a condenser of capacitive reactance 25 Ω. The combination is connected to an a.c. source of 110 V. The power factor of the circuit is:

1. 0.56

2. 0.64

3. 0.80

4. 0.33

The power factor of the given circuit is:
           

An inductor of inductance L and resistor of resistance R are joined in series and connected by a source of frequency ω. The power dissipated in the circuit is:

1. $\frac{(R^2+{\omega }^2{L}^2)}{V}$

2. $\frac{V^{2}R}{(R^2+{\omega }^2{L}^2)}$

3. $\frac{V}{(R^2+{\omega }^2{L}^2)}$

4. $\frac{\sqrt{R^2+{\omega }^2{L}^2}}{V^2}$

What is the average power dissipated in the ac circuit if current i = 100sin100t A and V=100sin(100t+π/3) volts?

1. 2500 W

2. 250 W

3. 5000 W

4. 4000 W

A resistance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes 'Z' the power drawn will be:
$1.$ $P{\left(\frac{R}{Z}\right)}^2$
$2.$ $P\sqrt{\frac{R}{Z}}$
$3.$ $P\left(\frac{R}{Z}\right)$
$4.$ $P$

An AC voltage source is connected to a series \(LCR\) circuit. When \(L\) is removed from the circuit, the phase difference between current and voltage is \(\frac{\pi}{3}\). If \(C\) is instead removed from the circuit, the phase difference is again \(\frac{\pi}{3}\) between current and voltage. The power factor of the circuit is:
1. \(0.5\)
2. \(1.0\)
3. \(-1.0\)
4. zero