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What is the ratio of true power in an ac circuit to apparent power delivered to the circuit?
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Introduction to power and power factor?
The power is the product between the magnitude of voltage and the magnitude of current. Whereas the power factor is a ratio between the active power and the apparent power.
What is the overal power factor is two motors connected in parallel?
It's the ratio of the total power of the two motors and their total apparent power (input side, of course.)
Why power factor using cos theta angle?
It's actually cos phi, where the Greek letter, 'phi', is the symbol for phase angle -the angle by which a load current lags or leads the supply current in an a.c. system (the Greek letter, 'theta', is used for the displacement of instantaneous values of current or voltage from the origin of a sine wave).The reason why power factor is a cosine requires you to understand the relationship between apparent power, true power, and reactive power. Apparent power is the vector sum of true power and reactive power, and can be represented, graphically, by the so-called 'power triangle'. In the power triangle, true power lies along the horizontal axis, reactive power lies along the perpendicular axis, and the apparent power forms the hypotenuse, and the angle between true power and apparent power represents the phase angle. By definition, power factor is the ratio between true power and apparent power, and this ratio corresponds to the cosine of the phase angle.From this, we can conclude that true power = apparent power x cos phi, where 'cos phi' is the 'factor' by which we must multiply apparent power to determine true power -i.e. the 'power factor'.
You are required to check the p f of an electric load No pf meter is available?
The answer is B. Because the voltmeter and the ammeter gives us the voltage and current respectively. and by the multiplication of both we get apparent power and by the Walt meter we get the actual power.. and the p.f. is the ratio of the apparent and actual power..
A circuit has a voltage of 240 volts and an inductive reactance of 30 ohms what is the current flow?
A circuit with a voltage of 240 volts and an inductive reactance of 30 ohms would have a current of 8 amperes.Reactance works just like resistance. The difference is that the phase angle between voltage and current is not zero, so the ratio of true power versus apparent power is not one.Phase angle and power factor depend on frequency. This was not specified in the question, so it is not answered.
Which relationship is true of power factor?
Power factor is:the ratio of true power to apparent powerthe ratio of resistance to impedancethe ratio of the voltage across a circuit's resistive component to the supply voltagethe cosine of the phase angleetc.
What is the ratio of apparent power to true power?
The ratio of apparent power to true power is called 'admittance', expressed in siemens. Admittance is the inverse of impedance.
A light draws current of 1.1 amps at 230 volts the power onput is 200w what is the circuit power factor?
The current's power factor is the true power divided by the apparent power. The Apparent Power is the volts multiplied by the amps. In this example, the ratio would be 200/253, or approximately .79.
What are cause of power factor?
Power factor is the ratio of true power versus apparent power. It is caused by the fact that current and voltage, in a reactive circuit (usually inductive, but also capacitive) are not in phase with each other.
What is powerfacter?
The ratio of active power (real power) and apparent power is called power factor ( pf ). Power Factor ( pf ) = Active Power / Apparent Power = .................. ( kvar )
What is power factor of an R L series circuit?
Power factor in any circuit is the ratio of the load's true power to its apparent power. It's also the cosine of the phase angle. In L-R circuits, it's described as a 'lagging power factor', because the load current lags the supply voltage.
What is power factor in electrical?
Ratio of voltage rating and current rating is called power factor in electricalAnswerPower factor can be defined in a number of ways -for example:cosine of the phase angleratio of true power to apparent powerIt has nothing to do with the ratio of voltage rating to current rating!
Power factor for pure resistive circuit?
ratio between true power and apparent power is called the power factor for a circuit Power factor =true power/apparent power also we conclude PF=power dissipated / actual power in pure resistive circuit if total resistance is made zero power factor will be zero
When is the power factor of a motor 1?
When the circuit is purely resistive or in resonance, i.e. capacitive and inductive reactance cancels out.Power factor is the ratio of apparent power over true power, and is the cosine of the phase angle between voltage and current.
Why power factor expressed in cosine angle?
The vector-relationship between apparent power, true power, and reactive power is represented by a right-angled triangle, whose hypotenuse represents apparent power and whose adjacent represents true power. Since power factor is defined as 'the ratio of true power to apparent power', you will find that this ratio corresponds to the cosine of the angle between them.
How can you develop power factor?
You do not 'develop' power factor; it is naturally-occurring in the sense that it is the ratio between the true power and the apparent power of a load in an a.c. system. It is numerically equal to the cosine of the phase angle -i.e. the angle by which the load current lags or leads the supply voltage.You can 'modify' the power factor of a circuit, for example, by adding capacitance to an inductive circuit, or the other way around.
Introduction to power and power factor?
The power is the product between the magnitude of voltage and the magnitude of current. Whereas the power factor is a ratio between the active power and the apparent power.
