Basic Electrical Engineering (3110005)

BE | Semester-1   Winter-2019 | 11-01-2020

Q3) (a)

Define the terms: - 1. Real power 2. Reactive power 3. Apparent power.

Real Power
“It is the actual power consumed in any circuit. It is given by product of rms voltage and rms current and cosine angle between voltage and current ( V I cos ϕ ). Unit is Watt (W) or kW.
 
Active Power = Real Power = P = I2 R = V I cos ϕ.
 
Reactive Power
“The power drawn by the circuit due to reactive component of current is called as reactive power. It is given by product of rms voltage and rms current and sine angle between voltage and current ( V I sin ϕ ). Unit is VAR or kVAR.
 
Reactive Power =Q = I2 X = V I sin ϕ.
 
Apparent Power
“It is the product of rms value of voltage and rms value of current. It is total power supplied to the circuit”. Unit is VA or kVA.
 
Apparent Power = S = V I