A single-phase voltage source  delivers a current,  A to a load.

The load power factor, correct up to two decimal places, is:

An electrical component has voltage drop , when the current through it is .

What is the average power dissipated over a half cycle corresponding to  ?

In an experiment to measure the active power drawn by a single-phase RL Load connected to an AC source through a  resistor, three voltmeters are connected as shown in the figure below. The voltmeter readings are as follows: . Assuming perfect resistors and ideal voltmeters, the Load-active power measured in this experiment, in W, is __________ (round off to one decimal place).

The voltage across and the current through a load are expressed as follows        

The average power in watts (round off to one decimal place) consumed by the load is _______.

In the figure, the voltages are  ,  and

. The circuit is in sinusoidal steady state, and,   and   are the average power outputs. Which one of the following statements is true?

The voltage across the circuit in the figure, and the current through it are given by the following expressions:

Where , If the average power delivered to the circuit is zero then the value of X (in Ampere) is ________ (up to 2 decimal places).

A source is supplying a load through a 2-phase, 3-wire transmission system as shown in figure below. The instantaneous voltage and current in phase-a are  V and A, respectively. Similarly for phase-b, the instantaneous voltage and current are A, respectively.         

The total instantaneous power flowing from the source to the load is

The voltage (V) and current ((A) across a load are as follows.

.

.

The average power consumed by the load, in W, is_____________.

A symmetrical square wave of 50% duty cycle has amplitude of ±15V and time period of . This square wave is applied across a series RLC circuit with  L=10mH and . The amplitude of the 5000 rad/s component of the capacitor voltage (in volt) is ____________.          

The total power dissipated in the circuit, shown in the figure, is 1kW. The voltmeter, across the load, reads 200V. The value of  is ____________

A single-phase load is supplied by a single –phase voltage source. If the current flowing from the Load to the source is  and if the voltage at the load terminals is , then the

The average power delivered to an impedance (4–j3) by a current  is

In the circuit shown, the three voltmeter readings are .

The power factor of the load is

In the circuit shown, the three voltmeter readings are .

If , the approximate power consumption in the load is         

An RLC circuit with relevant data is given below.

The power dissipated in the resistor R is

An energy meter connected to an immersion heater (resistive) operating on an AC 230 V, 50 Hz, AC single phase source reads 2.3 units (kWh) in 1 hour. The heater is removed from the supply and now connected to a 400 V peak square wave source of 150 Hz. The power in kW dissipated by the heater will be

Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is

In the circuit shown in Figure, what value of C will cause a unity power factor at the ac source?

A 240 V single-phase ac source is connected to a load with an impedance of .  A capacitor is connected in parallel with the load.  If the capacitor supplied 1250 VAR, the real power supplied by the source is

The voltage phasor of a circuit is  and the current phasor is A. The active and the reactive powers in the circuit are:

A constant voltage frequency sinusoidal voltage source of magnitude  is connected to a series circuit made of a resistance of 15Ω, a coil of winding resistance R and inductance L and a 50μF capacitor. The voltage across the 15Ω resistors is 30V, across the coil is 50V, across the capacitor is 40V, The voltage across the combination of the 15Ω resistor and the coil together is 72.11V. Determine the values of the inductance L, winding resistance R and the source voltage V.

A water boiler at home is switched on the a.c. mains supplying power at 230V/50Hz. The frequency of instantaneous power consumed by the boiler is

In figure calculate

(a) The power delivered by each source

(b) The power dissipated in each resistor