Active and Reactive power

Q. The average power delivered to an impedance $(4-j3)\Omega$ by a current $5cos(100\pi t+{100}^{\circ })A$ is

1. 44.2 W
2. 50 W
3. 62.5 W
4. 125 W

Q. In the circuit shown, the three voltmeter readings are $V_1=220V,V_2=122V,V_3=136V.$


If $R_L=5\Omega$ , the approximate power consumption in the load is

1. 700 W
2. 750 W
3. 800 W
4. 850 W

Q.

The total power dissipated in the circuit, shown in the figure, is 1 kW.



The voltmeter, across the load, reads 200 V. The value of $K_L$ is

1. 17.332

Q. In the figure, the voltage are $V_1\left(t\right)=100cos\left(\omega t\right),V_2\left(t\right)=100cos(\omega t+\frac{\pi }{18})and{V}_3\left(t\right)=100cos(\omega t+\frac{\pi }{36})$. The circuit is in sinusoidal steady-state, and R<< $\omega L$. $P_1,P_{2}and{P}_3$ are the average power outputs. Which one of the following statements is true?

1. $P_1=P_2=P_3=0$
2. $P_1<0,P_2>0,P_3>0$
3. $P_1<0,P_2>0,P_3<0$
4. $P_1>0,P_2<0,P_3>0$

Q.

An electric bulb is rated $220V$ and $100W$. When it is operated on $110V$, the power consumed will be

1. $100W$

2. $75W$

3. $50W$

4. $25W$

Q.
If $R_L=5\Omega$, the approximate power consumption in the load is

1. 700 W
2. 750 W
3. 800 W
4. 850 W

Q.

For the circuit, shown in the figure, the total real power delivered by the source to the load is kW.

1. 1.866

Q.
The power factor of the load is

1. 0.45
2. 0.50
3. 0.55
4. 0.60