Question

Average power is _________

(a) product of voltage and current

(b) product of average current and voltage

(c) product of instantaneous voltage and current

(d) product of absolute voltage and current

I had been asked this question in semester exam.

Question is taken from Electronic Energy Meter, Adjustments in Single Phase Energy meters topic in portion Measurement of Power and Related Parameters of Electrical Measurements

Answer 1

Right answer is (c) product of instantaneous voltage and current

For explanation: The average power is computed as the product of the instantaneous voltage across the load and the instantaneous current flowing through the load. A scaling device is used to bring the supply voltage to a proper level.