When is the power factor lagging , leading , unity ?

When is the power factor lagging , leading , unity ?
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1 Answer

Answer :

Power factor lagging in inductive load. Power factor leading in capacitive load is power factor unity in resistive load.
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Related questions

A transformer has negative voltage regulation when its load power factor is- (a) Zero (b) Unity (c) Leading (d) Lagging

Description : A transformer has negative voltage regulation when its load power factor is- (a) Zero (b) Unity (c) Leading (d) Lagging

Last Answer : Ans: C

When the voltage and the current developed in an AC circuit reach their peak values at the same time, the power factor is considered to be _____________. A. lagging B. leading C. unity D. infinity

Description : When the voltage and the current developed in an AC circuit reach their peak values at the same time, the power factor is considered to be _____________. A. lagging B. leading C. unity D. infinity

Last Answer : Answer: C

The power factor of industrial loads is generally (a) unity (b) lagging (c) leading (d) zero

Description : The power factor of industrial loads is generally (a) unity (b) lagging (c) leading (d) zero

Last Answer : (b) lagging

51 A transformer has negative voltage regulation when its load power factor is A. Zero B. Unity C. Leading D. Lagging

Description : 51 A transformer has negative voltage regulation when its load power factor is A. Zero B. Unity C. Leading D. Lagging

Last Answer : C. leading

A synchronous motor is operating on no-load at unity power factor. If the field current is increased, power factor will become (A) Leading & current will decrease (B) Lagging & current will increase. (C) Lagging & current will decrease. (D) Leading & current will increase.

Description : A synchronous motor is operating on no-load at unity power factor. If the field current is increased, power factor will become (A) Leading & current will decrease (B) Lagging & current will increase. (C) Lagging & current will decrease. (D) Leading & current will increase.

Last Answer : Ans: A Initially synchronous motor is operating at no load and unity power factor. When field current increases, the excitation will increase. Therefore, p.f will be leading and current will be I CosΦ < I

What is Lagging Power Factor ?

Description : What is Lagging Power Factor ?

Last Answer : When the inductive load of an AC circuit exceeds the capacitive load , the pf of the circuit is called lagging pf .

What is lagging power factor ?

Description : What is lagging power factor ?

Last Answer : When the amount of inductive load is greater than the capacitive load in a circuit then the power factor of that circuit is called lagging power factor.

What is lagging power factor ?

Description : What is lagging power factor ?

Last Answer : The cosine value of the phase angle between current and voltage in an inductive circuit is called lagging power factor.

In a transformer the voltage regulation will be zero when it operates at (A) unity p.f. (B) leading p.f. (C) lagging p.f. (D) zero p.f. leading.

Description : In a transformer the voltage regulation will be zero when it operates at (A) unity p.f. (B) leading p.f. (C) lagging p.f. (D) zero p.f. leading.

Last Answer : (B) leading p.f.

What is Unity Power Factor ?

Description : What is Unity Power Factor ?

Last Answer : There is no angular gap between current and voltage in pure resistance. That is, the phase angle of current and voltage is φ = 0, the power factor of that circuit is one or unit. This is called Unity Power Factor.

A two-winding single phase transformer has a voltage regulation of 4.5% at full-load and unity power-factor. At full-load and 0.80 power-factor lagging load the voltage regulation will be (A) 4.5%. (B) less than 4.5%. (C) more than 4.5%. (D) 4.5% or more than 4.5%.

Description : A two-winding single phase transformer has a voltage regulation of 4.5% at full-load and unity power-factor. At full-load and 0.80 power-factor lagging load the voltage regulation will be (A) 4.5%. (B) less than 4.5%. (C) more than 4.5%. (D) 4.5% or more than 4.5%.

Last Answer : (C) more than 4.5%.

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

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.

What is the Leading Power Factor ?

Description : What is the Leading Power Factor ?

Last Answer : When the capacitive load of an AC circuit exceeds the inductive load , the pf of the circuit is called the leading pf . Thank you!

What is the leading power factor ?

Description : What is the leading power factor ?

Last Answer : When the amount of capacitive load is more than the inductive load in a circuit then the power factor of that circuit is called leading power factor.

What is Leading Power Factor ?

Description : What is Leading Power Factor ?

Last Answer : If the current in the AC circuit is ahead of the voltage, it is called leading power factor.

If the excitation of an alternator operating in parallel is decreased below normal, its _____________. A. power factor will change in the lagging direction B. power factor will change in the leading direction C. ampere load will be greatly increased D. kilowatt load will be greatly decreased

Description : If the excitation of an alternator operating in parallel is decreased below normal, its _____________. A. power factor will change in the lagging direction B. power factor will change in the leading direction C. ampere load will be greatly increased D. kilowatt load will be greatly decreased

Last Answer : Answer: B

When voltage and current developed in an AC circuit reach their peak values at the same time, the power factor is _____________. A. lagging B. leading C. maximum D. minimum

Description : When voltage and current developed in an AC circuit reach their peak values at the same time, the power factor is _____________. A. lagging B. leading C. maximum D. minimum

Last Answer : Answer: C

If the excitation is increased to one of two alternators operating in parallel, the _____________. A. power factor will change in the lagging direction B. power factor will change in the leading direction C. kilowatt load will be greatly increased D. ampere load will be greatly decreased

Description : If the excitation is increased to one of two alternators operating in parallel, the _____________. A. power factor will change in the lagging direction B. power factor will change in the leading direction C. kilowatt load will be greatly increased D. ampere load will be greatly decreased

Last Answer : Answer: A

[75] Two transformers are connected in parallel. These transformers do not have equal percentage impedance which results A. Short-circuiting of the secondaries B. Power factor of one of the transformers is leading while that of the other lagging C. Transformers having higher copper losses will have negligible core losses D. Loading of the transformers not in proportion to their kVA ratings.

Description : [75] Two transformers are connected in parallel. These transformers do not have equal percentage impedance which results A. Short-circuiting of the secondaries B. Power factor of one of the ... have negligible core losses D. Loading of the transformers not in proportion to their kVA ratings.

Last Answer : D. Loading of the transformers not in proportion to their kVA ratings

An alternator is delivering rated current at rated voltage and 0.8 power-factor lagging case. If it is required to deliver rated current at rated voltage and 0.8 power-factor leading, the required excitation will be (A) less. (B) more. (C) more or less. (D) the same.

Description : An alternator is delivering rated current at rated voltage and 0.8 power-factor lagging case. If it is required to deliver rated current at rated voltage and 0.8 power-factor leading, the required excitation will be (A) less. (B) more. (C) more or less. (D) the same.

Last Answer : Ans: B Over excitation gives leading power factor and under excitation gives lagging p.f .

A motor which can conveniently be operated at lagging as well as leading power factors is the (A) squirrel cage induction motor. (B) wound rotor induction motor. (C) synchronous motor. (D) DC shunt motor.

Description : A motor which can conveniently be operated at lagging as well as leading power factors is the (A) squirrel cage induction motor. (B) wound rotor induction motor. (C) synchronous motor. (D) DC shunt motor.

Last Answer : (C) synchronous motor.

A motor which can conveniently be operated at lagging as well as leading power factors is the:...

Description : A motor which can conveniently be operated at lagging as well as leading power factors is the:   (A) squirrel cage induction motor (C) synchronous motor (B) wound rotor induction motor (D) DC shunt motor

Last Answer : A motor which can conveniently be operated at lagging as well as leading power factors is the: synchronous motor

Leading strand and lagging strand differences. -Biology

Description : Leading strand and lagging strand differences. -Biology

Last Answer : answer:

$ The enzymes which joins short pieces DNA in the laggins strand is called ligase. ! Lagging strand and leading strand are formed due to replication f

Description : $ The enzymes which joins short pieces DNA in the laggins strand is called ligase. ! Lagging strand and leading strand are formed due to replication f

Last Answer : $ The enzymes which joins short pieces DNA in the laggins strand is called ligase. ! Lagging strand and ... wrong D. If both As and R are wrong.

The division of kilowatt load between two paralleled alternators is determined by the _____________. A. amount of field excitation of the leading machine B. load-speed characteristics of the governors C. amount of field excitation to the lagging machine D. type of alternator

Description : The division of kilowatt load between two paralleled alternators is determined by the _____________. A. amount of field excitation of the leading machine B. load-speed characteristics of the governors C. amount of field excitation to the lagging machine D. type of alternator

Last Answer : Answer: B

The division of kilowatt load between two paralleled alternators is determined by the _____________. A. amount of field excitation to the leading machine B. load-speed characteristics of the governors C. amount of field excitation to the lagging machine D. number of field poles per alternator

Description : The division of kilowatt load between two paralleled alternators is determined by the _____________. A. amount of field excitation to the leading machine B. load-speed characteristics of the governors C. amount of field excitation to the lagging machine D. number of field poles per alternator

Last Answer : Answer: B

During DNA replication, Okazaki fragments are used to elongate (a) the lagging strand towards replication fork (b) the leading strand away from replication fork (c) the lagging strand away from the replication fork (d) the leading strand towards replication fork.

Description : During DNA replication, Okazaki fragments are used to elongate (a) the lagging strand towards replication fork (b) the leading strand away from replication fork (c) the lagging strand away from the replication fork (d) the leading strand towards replication fork.

Last Answer : (b) the leading strand away from replication fork

The arc voltage produced in A.C. circuit breaker is always (a) in phase with the arc current (b) lagging the arc current by 90" (c) leading the arc current by 90° (d) none of the above

Description : The arc voltage produced in A.C. circuit breaker is always (a) in phase with the arc current (b) lagging the arc current by 90" (c) leading the arc current by 90° (d) none of the above

Last Answer : (a) in phase with the arc current

During DNA replication, Okazaki fragments are used to elongate: (1) The lagging strand towards replication fork. (2) The leading strand away from replication fork. (3) The lagging strand away from the replication fork. (4) The leading strand towards replication fork.

Description : During DNA replication, Okazaki fragments are used to elongate: (1) The lagging strand towards replication fork. (2) The leading strand away from replication fork. (3) The lagging strand away from the replication fork. (4) The leading strand towards replication fork.

Last Answer : (3) The lagging strand away from the replication fork.

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

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.

Explain lagging quantity and leading quantity, explain this concept with voltage and current waveform

Description : Explain lagging quantity and leading quantity, explain this concept with voltage and current waveform

Last Answer : When two alternating quantities attain their respective zero or peak values simultaneously, the quantities are said to be in-phase quantities. When the quantities do not attain their respective zero or ... current is leading the voltage or the voltage is said to be lagging behind the current.

What is the best economic power factor ?

Description : What is the best economic power factor ?

Last Answer : This means that raising the power factor results in maximum annual savings , in which case the value of the power factor is called the best saving power factor.

What happens if the value of power factor is low ?

Description : What happens if the value of power factor is low ?

Last Answer : ( a) Current flows more , ( b) Copper loss increases , ( c) Heat increases , ( d) Output decreases , ( e) Voltage drop increases , ( f) Different electrical machinery heats up quickly. , ( G) The life span of various electrical machinery and appliances is reduced.

What is the power factor in pure resistive , capacitive , inductive load ?

Description : What is the power factor in pure resistive , capacitive , inductive load ?

Last Answer : Answer : Power factor cosΦ = 1 in pure resistive load, cosΦ = 0 in capacitive load , cosΦ = 0 in inductive load .

How many types of power factor ?

Description : How many types of power factor ?

Last Answer : Three types , namely , 1) lagging power factor , 2) leading power factor , 3) unity power

What is the effect of resistance and reactance on power factor ?

Description : What is the effect of resistance and reactance on power factor ?

Last Answer : Power factor depends on resistance and reactance. As the resistance of the circuit increases, the phase angle between the current and the voltage decreases, resulting in an increase in the power factor ... current and the voltage increases, resulting in a decrease in the power factor of the circuit.

What is Power Factor ?

Description : What is Power Factor ?

Last Answer : The phase factor or the cosine value of the angular interval between the voltage and current of an AC circuit is called the power factor.

What is a Power Factor Meter ?

Description : What is a Power Factor Meter ?

Last Answer : The cosine angle between voltage and current is called power factor

What is the value of power factor ?

Description : What is the value of power factor ?

Last Answer : The value of power factor is Cos Theta

What is the power factor expressed by ?

Description : What is the power factor expressed by ?

Last Answer : The power factor is expressed by cos theta.

Lagging Power Factor What ?

Last Answer : a . C. _ On the circuit Capacitive Of load Than Inductive Load More If so , the current Of voltage Later Location By , of the circuit This In condition Power To the factor Lagging Power Factor Says. This To the circuit Inductive Circuit Says.

When Alternator excitation increases and machine is operating at lagging power factor then a) I increase b) I decreases c) No effect on current d) None

Description : When Alternator excitation increases and machine is operating at lagging power factor then a) I increase b) I decreases c) No effect on current d) None

Last Answer : Ans: I increase

A three-phase synchronous motor has a terminal voltage of 460 V and a terminal current of 120 A at a power factor of 0.95 lagging, synchronous reactance of 1.68 ohm and the field current is 47 A. The field to armature mutual inductance of the synchronous motor is _____________.

Description : A three-phase synchronous motor has a terminal voltage of 460 V and a terminal current of 120 A at a power factor of 0.95 lagging, synchronous reactance of 1.68 ohm and the field current is 47 A. The field to armature mutual ... _____________.      (a). 20mH   (b). 16mH   (c). 24mH   (d). 22mH

Last Answer : 22

A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction

Description : A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction is  (A) magnetizing (B) demagnetizing (C) cross-magnetizing (D) ineffective

Last Answer : A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction is demagnetizing 

A 400 V, 50 Hz 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging.

Description : A 400 V, 50 Hz 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging. The stator and rotor copper losses are 1.5 kW and 900 W respectively. The friction and windage losses are 1050 W and the ... the motor will be (A) 23.06 kW (B) 24.11 kW (C) 25.01 kW (D) 26.21 kW

Last Answer : A 400 V, 50 Hz 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging. The stator and rotor copper losses are 1.5 kW and 900 W respectively. The friction and windage losses are 1050 W and the core losses are 1200 W. The air-gap power of the motor will be 25.01 kW

If the lagging power factor of the load decreases, the line losses will

Description : If the lagging power factor of the load decreases, the line losses will (A) Decrease (B) Increase (C) Flrst decrease and then Increase (D) Remain same

Last Answer : If the lagging power factor of the load decreases, the line losses will Increase

In a synchronous generator delivering lagging power factor load

Description : In a synchronous generator delivering lagging power factor load  (1) the excitation emf leads terminal voltage by the power angle (2) the excitation emf lags terminal voltage by the power angle (3) ... by the power factor angle (4) excitation emf lags the terminal voltage by the power factor angle

Last Answer : In a synchronous generator delivering lagging power factor load the excitation emf leads terminal voltage by the power angle

An alternator is delivering rated current at rated voltage and 0.8 power-factor lagging. For delivering rated...

Description : An alternator is delivering rated current at rated voltage and 0.8 power-factor lagging. For delivering rated current at rated voltage and 0.8 poWer—factor leading, the required excitation will be:  (A) less  (B) more (C) more or less (D) the same

Last Answer : An alternator is delivering rated current at rated voltage and 0.8 power -factor lagging. For delivering rated current at rated voltage and 0.8 power -factor leading, the required excitation will be: more 

A three phase transmission line delivers a load of 5 MW at 0.8 power factor lagging. Resistance of each...

Description : A three phase transmission line delivers a load of 5 MW at 0.8 power factor lagging. Resistance of each conductor is 0.5 ohm / km. Receiving end voltage is 33 kV. If the line loss is not to exceed 10%, determine the length of the line.  (A) 7 km (B) 27.9 km (C) 56.8 km (D) 13.9 km

Last Answer : B

A single phase 60 Hz generator supplies an inductive load of 4500kW at a power factor of 0.80 lagging ...

Description : A single phase 60 Hz generator supplies an inductive load of 4500kW at a power factor of 0.80 lagging by means of a 20 km long overhead transmission line. The line resistance and inductance are 0.0195 ohm and 0.60 mH ... voltage regulation of the line.  (A) 12.59% (B) 16.34% (C) 32.68% (D) 41.15% 

Last Answer : Answer is C