Question

Given below are two statements: one is labeled as Statement (1) and the other is labeled as Statement (2).
Statement (1): An LCR circuit connected to an AC source has maximum average power at resonance.
Statement (2): A resistor-only circuit with zero phase difference has maximum average power.
In the light of the above statements, choose the correct option:

• A. (1) and (2) both are correct
• B. (1) is correct but (2) is incorrect
• C. (1) is incorrect but (2) is correct
• D. Both (1) and (2) are incorrect

Answer 1

Answer: (A)

(1) and (2) both are correct

Answer 2

Statement (1) is correct. An LCR circuit connected to an AC source has maximum average power at resonance. At resonance, the reactive components of the circuit cancel each other out, leaving only the resistance to limit the flow of current. This results in maximum current flow and maximum power transfer to the circuit.
Statement (2) is incorrect. A resistor only circuit with zero phase difference does not necessarily have maximum average power. The power in a resistor only circuit is given by P =$\frac{V^2}{R}$, where V is the voltage across the resistor and R is its resistance. Maximum power occurs when the voltage across the resistor is at its maximum. This occurs when the circuit has a phase difference of 90 degrees, not zero.
Therefore, the correct option is (1) is correct but (2) is incorrect.
Answer. A