Important Questions On Difference Between kVA And kW

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kW, also known as the true power, is the actual power which is consumed by the circuit.

This power is consumed by the load in the circuit.
Whereas kVA is known as the apparent power, it is the power that a source is capable of providing to the load in the circuit.
kW is affected by the power factor but kVA is independent of the power factor.

Very Short Answer Questions (1 Mark)

Ques. Which unit in kVA and kW has a higher value?

Ans. Both kW and kVA have their own significant uses and value. kW is the unit of real power whereas kVA is a unit of apparent power or some real power plus reactive power. The power factor, until defined and known, is, therefore, an approximate value moreover 0.8. And the value of kVA will always be higher than the value for kW.

Ques. Is 1kw equal to 1kva?

Ans. The unit is equivalent to 3,600,000 joules. The kilovolt-ampere (kVA) is the power rating of a circuit conveying 1,000 volts and an ampere or 1,000 amperes and a volt. A single kilovolt-ampere is comparable to a kilowatt.

Ques. Convert the Real Power in Watts to Apparent Power in kVA.

Ans. S(kVA) = P(W) / (1000 × PF)W

Watts divided by 1000 times the power factor is equal to kilovolt-amps.

kVA = kW / (1000 × PF

Ques. Why are generators rated in kVA and not kW?

Ans. The kVA is apparent power and doesn’t take into account the power factor of the kW real rower.

Ques. State full form and formula of kW.

Ans. The fullform of kW is kilo-watt and the formula is P(kW) = P(W) / 1,000.

Short Answer Questions (2 Marks)

Ques. Define kVA and kW.

Ans. kVA is 1,000-volt amps. A volt is an electrical pressure and an amp is an electrical current. Apparent power, which is the absolute value of complex power, S, is equal to the product of the volts and amps.

kW is the amount of 'actual power' an electrical system has. This shows you how much power is being converted into useful, working output.

Ques. How do you calculate kVA?

Ans. Calculation of kVA is specified below:

S_(kVA) = √3 × I_(A) × V_L-L(V) / 1000.

So kilovolt-amps are equal to √3 times amps times volts divided by 1000.

kilovolt-amps = √3 × amps × volts / 1000.

kVA = √3 × A ⋅ V / 1000.

S = √3 × 12A × 190V / 1000

= 3.949kVA.

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Ques. Provide the relation of KVA and KW for DC and AC circuits.

Ans. The relation of KVA and KW for DC and AC circuits is specified below:

For the AC circuit:

Power Factor >1 kW= kVA*PF

For the DC circuit:

Power Factor=1 kW= kVA

Ques. . What is the Power Factor?

Ans. The power factor defines the proportion between kilowatts (kW) and kilovolt amps (kVA) from an electrical load. It is also characterised as the cosine of the angle between current and voltage. In an electric power framework, a load with a low power factor draws more flow than a load with a high power factor for a similar measure of usable power moved.

The pf labelled in the generators relates the rating of both kVA and kW. Generators with higher power factors more effectively move energy to the connected load, whereas generators with lower power factors result in expanded force costs. Power factor is the total measurement of effective incoming power being used in the electrical system.

Long Answer Questions (3 Marks)

Ques. Why are generators and alternators determined in kVA and not in kW?

Ans. The generators and alternators are determined in kVA and not in kW for the following reasons.

The alternator conductors are determined for a fluent and clear current. Protection at an attractive framework is intended for a positive voltage-free power factor of Cos θ of the load. So, apparent power estimated in kVA is seen as the rated power of the alternator.

The primary manufacturers consider during structuring electrical gadgets and machines which give electric force such as alternators and generators a burden and force factor. Because they don't accurately know about the power factors and the burden that will be associated with the gadget and machines. Therefore, they design and rate the electrical device based on its maximum output of current which the conductors can safely carry.

Ques. What is the ideal value of the power factor in the circuit? And why does it lack in achieving the demanded value in large circuitry?

Ans. The power factor is determined by the cosine of the angle between kVA and kW. The phase difference between kVA and kW which is angle =0 and cos(0)=1 is zero. Hence, the ideal value of the power factor is 1.

This value of the power factor implies the energy being generated in the circuit is used wholly, adding to it, this also provides maximum efficiency. Although in larger circuitry, the capacitors and inductors bring lead or lag and therefore the angle becomes greater than zero and makes it difficult to achieve the ideal value in this case.

Very Long Answer Questions (5 Marks)

Ques. State the difference between kVA and kW.

Ans. Differences between kVA and kW are:

kVA	kW
kVA is used to represent apparent power.	kW is used to represent actual power.
Full form of kVA is kilovolt amperes.	Full form of kW is kilowatts.
The formula for converting kVA into kW is: Apparent power (kVA) x power factor (pf) = actual power (kW)	The formula for converting kW into kVA is: Actual power (kW) / power factor (pf) = apparent power (kVA)
kVA is independent of the load power factor.	Kilowatts is proportional to the load power factor.
kVA is the unit of apparent power	kW is the unit of electric power
kVA is the amount of power that alternators, transformers and UPS are capable of delivering the load connected to them.	kW is basically the measure of true power consumed by the load.

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