Question

Statement I: When AC circuit contains resistor only, its power is minimum.
Statement II: Power of a circuit is independent of phase angle.

• A. If both statements are true and statement II is the correct explanation of statement $I$.
• B. If both statements are true but statement II is not the correct explanation of statement $I$.
• C. If statement $I$ is true but statement II is false.
• D. If both statements are false.

Answer 1

Answer: (D)

The power of an $A C$ circuit is given by $P=E I \cos \phi$ where $\cos \phi$ is power factor and $\phi$ is phase angle. In case of circuit containing resistance only, phase angle is zero and power factor is equal to one. Therefore power is maximum in case of circuit containing resistor only.