# The product of apparent power and cosine of the phase angle between circuit voltage and current is?

The product of apparent power and cosine of the phase angle between circuit voltage and current is?

The product of apparent power and cosine of the phase angle between circuit voltage and current is true power.

In parllpar reasonans RLC circuit the current is

## Related questions

Description : The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is?

Last Answer : The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is 6 kVAR.

Description : The ratio of active power to apparent power is known as____ factor.

Last Answer : The ratio of active power to apparent power is known as power factor.

Description : Active power and apparent power are represented by?

Last Answer : Active power and apparent power are represented by kW and kVA.

Description : What will be the phase angle between two alternating waves of equal frequency, when one wave attains maximum value the other is at zero value ?

Last Answer : 90° will be the phase angle between two alternating waves of equal frequency, when one wave attains maximum value the other is at zero value.

Description : Two waves of the same frequency have opposite phase when the phase angle between them is?

Last Answer : Two waves of the same frequency have opposite phase when the phase angle between them is 180°.

Description : Explain the concept of lagging and leading phase angle by waveform.

Last Answer : i) Leading phase angle :  When two ac quantities of same frequency do not attain their respective zero or peak values simultaneously, then the quantities are said to be out-of-phase quantities. The ... Similarly, in the second diagram, the voltage is said to be lagging the current by  Φ.

Description : Phase margin is the amount of angle to make the system  (1) Oscillatory (2) Stable (3) Unstable (4) Exponential

Last Answer : Phase margin is the amount of angle to make the system Unstable

Description : Express the following functions in cosine form

Last Answer : Express the following functions in cosine form

Description : The r.m.s. value of pure cosine function is?

Last Answer : 0.707 of peak value

Description : The power consumed in a circuit element will be least when the phase difference between the current and voltage is?

Last Answer : The power consumed in a circuit element will be least when the phase difference between the current and voltage is 90°.

Description : The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45o and 15o, respectively. The direct axis and quadrature axis currents, respectively, are (A) 0.5 pu ... pu, 0.5 pu (C) 0.707 pu, 0.707 pu (D) 0.5 pu, 0.5 pu

Last Answer : The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45o and 15o, respectively. The direct axis and quadrature axis currents, respectively, are 0.866 pu, 0.5 pu

Description : The synchronous motor will develop maximum power when the load angle is?

Last Answer : The synchronous motor will develop maximum power when the load angle is 900.

Description : List any two methods of reactive power measurement in 3 phase circuit.

Last Answer : Methods of reactive power measurement in 3 phase circuit: (i) Two single phase wattmeter method (ii) One single phase wattmeter method

Description : In an alternator at lagging power factor the generated voltage per phase as compared to that at unity power factor?

Last Answer : In an alternator, at lagging power factor the generated voltage per phase as compared to that at unity power factor must be more than terminal voltage.

Description : With a neat sketch explain working of 1 phase dynamometer type power factor meter.

Last Answer : Working of 1 phase dynamometer type power factor meter : The current coil is connected in series with load. Two pressure coils marked as A and B are connected across the supply terminals ... becomes stationary and the pointer shows steady deflection corresponding to the power factor of the load.

Description : State any two disadvantages of one wattmeter method of measurement of 3 phase power.

Last Answer : State any two disadvantages of one wattmeter method of measurement of 3 phase power. Disadvantages of one wattmeter method:- 1. Only used for balanced load 2. It can not be used for ... connection then neutral point must be available 4. Delta connection must be opened to connect current coil.

Description : What is the power factor when a single phase watt meter operating on 200 V and 5 A for 5 hours makes 2016 revolutions and the meter constant in revolution is 420? A) 0.04 B) 1.04 C) 0.96 D) None of these

Last Answer : What is the power factor when a single phase watt meter operating on 200 V and 5 A for 5 hours makes 2016 revolutions and the meter constant in revolution is 420? A) 0.04 B) 1.04 C) 0.96 D) None of these

Last Answer : The power factor of a single phase load can be calculated if the instruments available are three ammeters or three voltmeters.

Last Answer : In a single phase power factor meter the phase difference between the currents in the two pressure coils is exactly 90°.

Last Answer : The two pressure coils of a single phase power factor meter have the same dimensions and the same number of turns.

Description : When the firing angle a of a single-phase, fully controlled rectifier feeding constant direct current into a load is 30°, the displacement power factor of the rectifier is

Last Answer : When the firing angle a of a single-phase, fully controlled rectifier feeding constant direct current into a load is 30°, the displacement power factor of the rectifier is √3/2

Last Answer : If the current in a capacitor leads the voltage by 80°, the loss angle of the capacitor is 10°.

Description : How to find total impedance Z, current I and Impedance angle ?

Last Answer : How to find total impedance Z, current I and Impedance angle ?

Description : The r.m.s. value of a sinusoidal A.C. current is equal to its value at an angle of______degrees.

Description : The phase difference between voltage and current wave through a circuit element is given as 30°. The essential condition is that?

Last Answer : The phase difference between voltage and current wave through a circuit element is given as 30°. The essential condition is that both waves must have same frequency.

Description : Define: i) Firing angle ii) Conduction angle

Last Answer : i) Firing angle: The firing angle of a thyristor is defined as the angle between the zero crossing of the applied voltage and the instant at which the thyristor is triggered or fired. It is a ... off. It is a measure of the duration for which the thyristor conducts current during each AC cycle.

Description : Torque angle for the synchronous machine is the angle between (A) stator magnetic field and rotor magnetic field (B) stator magnetic field and net magnetic field in the air gap (C) rotor magnetic field and net magnetic field in the air gap (D) excitation voltage and impedance voltage drop

Last Answer : Torque angle for the synchronous machine is the angle between rotor magnetic field and net magnetic field in the air gap

Description : Tangent of angle of friction is equal to?

Last Answer : Tangent of angle of friction is equal to coefficient of friction.

Description : Angle of friction is the?

Last Answer : Angle of friction is the angle between normal reaction and the resultant of normal reaction and the limiting friction.

Last Answer : The coupling angle or load angle of synchronous motor is defined as the angle between the rotor and the stator poles of opposite polarity.

Description : What is meant by firing angle of thyristor?

Last Answer : The point at which SCR is triggered is known as firings angle of thyristor.

Description : What is the maximum value of torque angle in synchronous motor?

Last Answer : The maximum value of torque angle in synchronous motor is 90 degrees electrical.

Description : what is firing angle?

Last Answer : Firing angle is time in electrical degrees from the instant the valve voltage is positive to the application of firing pulse to the valve (start of conduction). Also called delay angle.

Description : Explain the principle of ON-OFF control and phase control of AC voltage controller with suitable circuit and waveforms.

Last Answer : The integral cycle control (on-off control) and phase angle control are the two types of AC voltage controller. The principle of ON-OFF control: The on-off control is also called an integral cycle ... control. In phase control, the switch is on for some period of each cycle.

Description : Write the relation between phase and line current, phase and line voltage for Star connection.

Last Answer : Line voltage is equal to root three times of phase voltage and line and phase currents are equal in star connection

Description : A single core cable is designed to work for a single phase system with a peak voltage of 220 kV. The maximum permissible stress in the dielectric is not to exceed 20 kV/mm. For economical size, the overall core diameter of the cable is (A) 28.2 mm (B) 26.4 mm (C) 24.4 mm (D) 22.0 mm

Last Answer : A single core cable is designed to work for a single phase system with a peak voltage of 220 kV. The maximum permissible stress in the dielectric is not to exceed 20 kV/mm. For economical size, the overall core diameter of the cable is 22.0 mm

Description : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole)  (A) has q -axis current only (B) has d -axis current only (C) has both d and q axis currents (D) cannot be divided between q and d axis currents

Last Answer : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole) has d -axis current only

Description : Define balanced and unbalanced load in three phase circuit.

Last Answer : Balanced Load: When all the imedances of 3 phases are equal in magnitude and of same nature then load is said to be balanced.  Unbalanced Load: When all the imedances of 3 phases are not equal in magnitude and of different nature then load is said to be unbalanced.

Description : A single phase transformer has resistance and reactance of 0.2 pu and 0.6 pu respectively. Its pu voltage regulation at 0.8 pf lagging would he

Last Answer : A single phase transformer has resistance and reactance of 0.2 pu and 0.6 pu respectively. Its pu voltage regulation at 0.8 pf lagging would he 0.52

Description : The potential coil of a single phase dynamometer wattmeter has 4840 Ohm resistance. Voltage across the load is 220 V. With the potential coil connected on the load side, the meter indicates 100 W. Approximate percentage error due to wattmeter connection is (A) 11% (B) 9% (C) 1.1% (D) 3%

Last Answer : The potential coil of a single phase dynamometer wattmeter has 4840 Ohm resistance. Voltage across the load is 220 V. With the potential coil connected on the load side, the meter indicates 100 W. Approximate percentage error due to wattmeter connection is 11%

Description : What is the difference between line and phase voltage?

Last Answer : Line voltage  is  voltage  between two  phases R &Y  (415 v)  while  phase  voltage  is  the  voltage  between  one  phase and  a neutral  B &  N   (240 v).

Description : Why the read of 3 phase voltage is 440?

Last Answer : The  read  of  a  phase  voltage  should be approximatly  240v. This  is  because  line  voltage  equals  to quberoot of  phase  voltage.

Description : What is the voltage in 3 phase line?

Last Answer : between 430 to 440 v

Description : State any four applications of three phase circuits.

Last Answer : The application of three phase circuits are 1. Three phase circuit is used for power transmission over long distances. 2. Three phase circuit can produce rotating magnetic field 3. Three phase ... three phase Motors and Transformers. 4. Three phase circuit is used for power converters circuits.

Description : In a 3-phase converter circuit during commutation when one SCR in one phase is turned on to turn-off an SCR in another phase, results in (A) voltage notching (B) harmonic distortion (C) voltage sag (D) voltage swell

Last Answer : In a 3-phase converter circuit during commutation when one SCR in one phase is turned on to turn-off an SCR in another phase, results in voltage notching

Last Answer : Starting winding of a single phase motor of a refrigerator is disconnected from the circuit by means of a magnetic relay.

Description : Diffecult questions