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For Single Phase,

P = VI cos (theta)

therefore cos(theta) = P/VI

here

P = Power

V = voltage

I = current

theta = phase angle current to voltage

cos(theta) = power factor

For Three Phase,

P = 3VI cos(theta)

where V = phase voltage and I = phase current and theta = phase angle

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13y ago
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16y ago

Reactive Power=J* V(rms)* I(rms)*sin(angle of voltage-angle of current)

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9y ago

The definition of reactive power is power that is supplied from and AC circuit. This occurs when the voltage and current are not in phase.

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14y ago

Power where the voltage and current are not in phase (specifically, they are 90 degrees out of phase with eachother).

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13y ago

capacitive reactancE Xc =1/2*pi*f*c

where,

Xc = reactance

pi= 3.14

f= frequency of supply

c= capacitance

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Q: What is the definition of reactive power?
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Why reactive power is named as reactive?

Actually reactive power is a power which flows in between load to source which is a reactive action of the power given from source to load.the given power to load will not be utilised fully.some power will be oscillating from load to source.this is called reactive power.


What happens to reactive power in a circuit that has both inductance and capacitance?

Inductors are considered to be a load for reactive power, meaning that they will draw reactive power from the system. Capacitors are considered to be sourced of reactive power, they feed reactive power into the system. If you have a circuit that is at unity (balanced with inductors and capacitors) no reactive power will be drawn from the source. You will have unity power factor. If your circuit is more inductive than capacitive it will be drawing reactive power from the source. The opposite is also true for capacitors.


Which excitation synchronous motor drawn reactive power?

Hi, Under excitation - inductive reactive power Over excitation - Capacitive reactive power.


Is reactive power greater than true power?

Use a wattmeter, as it only reads 'real power' of your load. Use an ammeter and a voltmeter, and the product of the two readings will give you 'apparent power' of your load. Since apparent power is the vector sum of real power and reactive power, use the following equation to find the reactive power of your load: (reactive power)2 = (apparent power)2 - (real power)2


What is the power factor of AC generator when the reactive power is equal to zero?

Per factor is 1 when reactive power is zero.

Related questions

What is the definition to Reactivity?

The definition for the word reactivity is "the state or power of being reactive or the degree to which a thing is reactive."


Why reactive power is named as reactive?

Actually reactive power is a power which flows in between load to source which is a reactive action of the power given from source to load.the given power to load will not be utilised fully.some power will be oscillating from load to source.this is called reactive power.


What is the definition of natural power?

In power transmission, there is a certain amount of power where reactive power is not needed and this is natural power. For example, a network with a voltage level of 380kv and a wave impedance of 200 ohm needs 722MW power in order not to require reactive power for transmission. Formula Pnat=(voltage level)squared divided by wave impedance.


What happens to reactive power in a circuit that has both inductance and capacitance?

Inductors are considered to be a load for reactive power, meaning that they will draw reactive power from the system. Capacitors are considered to be sourced of reactive power, they feed reactive power into the system. If you have a circuit that is at unity (balanced with inductors and capacitors) no reactive power will be drawn from the source. You will have unity power factor. If your circuit is more inductive than capacitive it will be drawing reactive power from the source. The opposite is also true for capacitors.


Why wattmeter measure the reactive power?

A watt meter will measure active power, not reactive power.


Which line requires compensation?

Basically an AC transmission line require compensation in terms of reactive power. To push the active power across a transmission line certain amount of reactive power is necessary. In AC transmission line reactive power is generated and consumed. Generator is responsible for the production of reactive and active power both. Than this reactive power is consumed by the load and transmission line. Additional reactive power s supplied by the capacitor. This extra power supplied by the capacitor is termed as reactive power compensation. Requirement of this reactive power is there because reactive power is necessary to maintain the voltage stability.


How can you reduce reactive power?

If, for example, the reactive power of a load is due to its inductance, then installing a capacitor in parallel with the load will reduce the overall reactive power.


Which excitation synchronous motor drawn reactive power?

Hi, Under excitation - inductive reactive power Over excitation - Capacitive reactive power.


Is that the reactive power is a combination of both reactive power and imaginary power?

No. It is apparent power (expressed in volt amperes) that is the combination (vector sum) of true power (expressed in watts) and reactive power (expressed in reactive volt amperes). 'Imaginary power' is simply another name for 'reactive power' -where 'imaginary' is simply mathematicians-speak for 'quadrature' or 'right angles'.


Is reactive power a vector or scalar?

I am not sure what exactly you mean by "reactive power" (I guess you mean electrical reactive power), but power is the ratio of energy for a period of time. So that makes power (and reactive power as well) a scalar, since you can describe it with only one number. The fact that electrical reactive power is drawn on a XY plane, should not confuse you.


Is reactive power greater than true power?

Use a wattmeter, as it only reads 'real power' of your load. Use an ammeter and a voltmeter, and the product of the two readings will give you 'apparent power' of your load. Since apparent power is the vector sum of real power and reactive power, use the following equation to find the reactive power of your load: (reactive power)2 = (apparent power)2 - (real power)2


What is the power factor of AC generator when the reactive power is equal to zero?

Per factor is 1 when reactive power is zero.