The power factor in a circuit connected to an AC power supply has a value which is:

Question

The power factor in a circuit connected to an AC power supply has a value which is: (A) unity when the circuit contains only inductance (B) unity when the circuit contains only resistance (C) zero when the circuit contains an ideal resistance only (D) unity when the circuit contains an ideal capacitance only

Tardigrade Admin · Accepted Answer

Power factor, cos φ =(R/Z) When circuit contains only resistance, then Z=R ∴ cos φ =(R/R)=1

Q. The power factor in a circuit connected to an AC power supply has a value which is:

unity when the circuit contains only inductance

unity when the circuit contains only resistance

zero when the circuit contains an ideal resistance only

unity when the circuit contains an ideal capacitance only

Power factor, $cos ϕ = \frac{R}{Z}$
When circuit contains only resistance, then
$Z = R$
$∴$ $cos ϕ = \frac{R}{R} = 1$

Q. The power factor in a circuit connected to an AC power supply has a value which is:

unity when the circuit contains only inductance

unity when the circuit contains only resistance

zero when the circuit contains an ideal resistance only

unity when the circuit contains an ideal capacitance only

Power factor, cosϕ=ZR​ When circuit contains only resistance, then Z=R ∴ cosϕ=RR​=1

Power factor, $cos ϕ = \frac{R}{Z}$
When circuit contains only resistance, then
$Z = R$
$∴$ $cos ϕ = \frac{R}{R} = 1$