0
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
Wiki User
∙ 12y ago
Add your answer:
Earn +20 pts
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.
What affect the phase angle?
Apparent power is the vector sum of a load's true power and its reactive power. If you draw a 'power diagram', the phase angle will be the angle between the true power and the apparent power. If true power is fixed, then increasing the phase angle will result in a greater value of apparent power.
What is the relationship of the reactive volt-amperes to the total volt-amperes in a unity-power factor circuit?
If you have unity power factor, p.f.=1, then the real power P must equal the total power S. Therefore, there is no reactive power being used, Q=0.Alternative AnswerApparent power is the phasor (vector) sum of true power and reactive power: (apparent power)2 = (true power)2 x (reactive power)2
What kind of power is required to supply both resistive and reactive components of a load or loads?
You may be fishing for the answer "AC" or "alternating current", sinceno reactive component of power is developed in response to DC.AnswerSince true power (in watts) is associated with resistive components, and reactive power (in reactive volt amperes) is associated with reactive loads, the vector-sum of these is called apparent power (in volt amperes). So the answer you are looking for is apparent power.
Why reactive power flow is undesired?
Reactive power is useless part of the energy supplied. A minimum value of reactive power is always required to keep the voltage constant and supply the useful active power. In order to understand the concept completely, do refer PV and QV curves which explains the interdependency of active power, reactive power and voltage.
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.
What affect the phase angle?
Apparent power is the vector sum of a load's true power and its reactive power. If you draw a 'power diagram', the phase angle will be the angle between the true power and the apparent power. If true power is fixed, then increasing the phase angle will result in a greater value of apparent power.
True power divided by apparent power?
Real Power: The actual power in Watts or K-Watts in AC or DC Circuits Apparent power: The Power in Inductive or Capacitive Circuits have Phase Lag & Lead measured in Volt Amperes VA or Kilo Volt Amperes KVA
What is the apparent power of an RLC parallel circuit if the true power of the resistor is 4800 watts the reative power of the inductor is 7200 and the reactive power of the capacitor is 3600?
Apparent power is the vectorial sum of the true power and reactive power. In this case, the total reactive power is the difference between 7200 var and 3600 var -i.e. 3600 var.So you can now use the equation,(apparent power)2 = (true power)2 + (total reactive power)2,to determine your answer.
What is reactive power and its significance?
'Reactive power' is the rate at which energy is stored in an electric or magnetic field, and returned to the supply. To differentiate between reactive power and true power (the rate of heat transfer and of work), and for no other reason, it is expressed in reactive volt amperes (var) rather than in watts (W). Its significance is that it is necessary to establish and sustain electric and magnetic fields.
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'.
What is the relationship of the reactive volt-amperes to the total volt-amperes in a unity-power factor circuit?
If you have unity power factor, p.f.=1, then the real power P must equal the total power S. Therefore, there is no reactive power being used, Q=0.Alternative AnswerApparent power is the phasor (vector) sum of true power and reactive power: (apparent power)2 = (true power)2 x (reactive power)2
What actually you understand the meaning of power factor?
In a.c. circuits, there are two different 'types' of 'power': 'true power' and 'reactive power'. 'True power' describes the rate at which the energy supplied to a load is either lost to the surroundings through heat transfer or which does useful work (such as providing the output from a motor), and we measure this in watts. 'Reactive power' describes the rate at which energy is alternately stored in the load's magnetic or electric fields and, then, returned to the supply as the current increases and decreases every quarter-cycle, and we measure this in reactive volt amperes. Some books describe reactive power as the rate at which this energy 'sloshes back and forth, between the supply and the load's magnetic or electric fields', because it represents the movement of energy but not a loss of that energy! For a given load, reactive power increases as the phase angle (the angle between the load current and the supply voltage) increases. Obviously, therefore, the greater a load's reactive power, the greater its apparent power. The 'total' rate at which energy is moving in an a.c. circuit is the vector sum of true power and reactive power, and we call this the circuit's 'apparent power', expressed in volt amperes. Power factor is simply the ratio between true power (expressed in watts) and apparent power (expressed in volt amperes) or the cosine of the phase angle. Loads with low power factors (i.e. large phase angles) draw far more current than is necessary for the energy consumed from the supply. So, low power-factor loads require unecessarily-large supply conductors if higher-than-normal voltage drops and line losses are to be avoided and are, therefore, undesirable.
What will be the power of a purely inductive circuit?
Its 'true power', expressed in watts, will be zero, while its 'reactive power', expressed in reactive volt amperes, will be the product of the voltage across the inductor and the current through it.
What kind of power is required to supply both resistive and reactive components of a load or loads?
You may be fishing for the answer "AC" or "alternating current", sinceno reactive component of power is developed in response to DC.AnswerSince true power (in watts) is associated with resistive components, and reactive power (in reactive volt amperes) is associated with reactive loads, the vector-sum of these is called apparent power (in volt amperes). So the answer you are looking for is apparent power.
How kvar is calculated?
There are various ways in which you can determine the reactive power (in reactive volt amperes) of a load. From the practical point of view, you can use a voltmeter and an ammeter and use the product of their readings to determine the apparent power (in volt amperes) of the load, and a wattmeter to determine the true power (in watts) of the load, then find the vectorial difference: (reactive power)2=(apparent power)2-(true power)2
Power factor is not greater than unity?
Yes. Power factor is never greater than one, nor less than negative one. It is the cosine of the phase angle, and is the ratio of true versus apparent power.A negative power factor can occur in the case of a generator.
