Answer Posted / induja
The apparent power is a combination of both reactive power and true power.Reactive loads such as inductors and capacitors dissipate zero power, yet the fact that they drop voltage and draw current gives the deceptive impression that they actually do dissipate power. This “phantom power†is called reactive power, and it is measured in a unit called Volt-Amps-Reactive (VAR), rather than watts. The mathematical symbol for reactive power is (unfortunately) the capital letter Q. The actual amount of power being used, or dissipated, in a circuit is called true power, and it is measured in watts (symbolized by the capital letter P, as always). The combination of reactive power and true power is called apparent power, and it is the product of a circuit's voltage and current, without reference to phase angle. Apparent power is measured in the unit of Volt-Amps (VA) and is symbolized by the capital letter S.
As a rule, true power is a function of a circuit's dissipative elements, usually resistances (R). Reactive power is a function of a circuit's reactance (X). Apparent power is a function of a circuit's total impedance (Z). Since we're dealing with scalar quantities for power calculation, any complex starting quantities such as voltage, current, and impedance must be represented by their polar magnitudes, not by real or imaginary rectangular components. For instance, if I'm calculating true power from current and resistance, I must use the polar magnitude for current, and not merely the “real†or “imaginary†portion of the current. If I'm calculating apparent power from voltage and impedance, both of these formerly complex quantities must be reduced to their polar magnitudes for the scalar arithmetic.
| Is This Answer Correct ? | 1 Yes | 1 No |
Post New Answer View All Answers
how commomn gate triggering is given for TRIAC ? other thyristor wont be efffected?
what is the Earth Voltages in Power Plants, Sub-stations, Industries, Residential & Commercial Buildings.
What is the difference between shortcircuit current, rated current of cable & MCB with example? What will be the size of cable required for 5.5 KW motor (Full load current 10 Amps approx.), Starting current with DOL is 120 Amps. Aprrox. Short circuit current with LLLG fault is 2000 Amps Approx.
Define newton's law of viscosity.
I need to connect a synchronous generator to the grid using automatic synchronization and two circuit breakers (one for synchronization, one for end connection to the grid), how to determinate the required diameter of the cables?
What type of fittings and electrical accessories can be install in radiation area ?
Explain how you intend to work under pressure to meet up with deadline target?
what questions will be asked for 11/33KV licence interview APSEB hyderabad. Can any one share question and answers.
What is a advantage of Self Reset Lockout ? On Fault breaker get trip & fault no longer exist then self reset lockout how inform us?
what is the formula to calculate voltage drop/loss on 66KV Transmission Line?
hi frnds...pls send me aptransco previous papers .....pls..pls,,,(madhar.rocking@gmail.com)and suggest me some websites
RATING OF LIGHTENING ARRESTER FOR 11 KV LINE IS 9 KV is ok ,but haw to calculate the KA rating?
define the non synchoronism of synchoronous machine in general g or m??
where was current transformer protection units used and why??