APPARENT POWER & POWER FACTOR
- Apparent factor S is the product of RMS values of voltage & current.
- It is measured in volt-amperes or VA to distinguish it from the average or real power which is measured in WATTS.
S = VrmsIrms
- The apparent power is so called because it seems apparent that the power should be the voltage-current product, by analogy with dc resistive circuits.
- Power factor is the cosine of the phase difference between the voltage & current. It is also the cosine of the angle of the load impedance if V is the voltage across the load and I is the current through it.
Pf = P / S = cos ( ɸv-ɸi )
- The apparent power is so called because it seems apparent that the power should be the voltage-current product, by analogy with dc resistive circuits.
- Power factor is the cosine of the phase difference between the voltage & current. It is also the cosine of the angle of the load impedance if V is the voltage across the load and I is the current through it.
Pf = P / S = cos ( ɸv-ɸi )
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