Question

What is the power factor in a pure resistive circuit?

(a) 0

(b) -1

(c) Infinity

(d) 1

This question was addressed to me in a national level competition.

This interesting question is from Power in AC Circuit : The Power Factor topic in portion Alternating Current of Physics – Class 12

Answer 1

Right option is (d) 1

Explanation: A circuit containing only a pure resistance in an AC circuit is known as a pure resistive AC Circuit. For a purely resistive circuit, the power factor is one, because the reactive power equals zero, i.e.

Φ = 0 ➔ Power factor (cos⁡0)=1