Assertion : The power in ac circuit is minimum if the circuit has only a resistor.
Reason : Power of a circuit is independent of the phase angle.

Options

A. If both assertion ans reason are true ans reaason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion istrue but reason is false.
D. If both assertion and reason are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states that "The power in an AC circuit is minimum if the circuit has only a resistor."

- In an AC circuit, the power (P) is given by the formula:
\[ P = V_{\text{rms}} \times I_{\text{rms}} \times \cos \phi \]
where \( \phi \) is the phase angle between the voltage and current.

- For a purely resistive circuit, the phase angle \( \phi \) is 0 degrees (or 0 radians), which means \( \cos \phi = 1 \). Therefore, the power is maximum, not minimum.

### Conclusion for Assertion:
The assertion is **false** because the power is maximum in a purely resistive circuit, not minimum.

### Step 2: Analyze the Reason
The reason states that "Power of a circuit is independent of the phase angle."

- From the power formula, we see that power is indeed dependent on the phase angle \( \phi \) since it directly affects the value of \( \cos \phi \).

- When \( \phi = 90^\circ \) (or \( \pi/2 \) radians), \( \cos \phi = 0 \), resulting in zero power. This shows that power is very much dependent on the phase angle.

### Conclusion for Reason:
The reason is **false** because the power in an AC circuit is dependent on the phase angle.

### Final Conclusion:
Since the assertion is false and the reason is also false, the correct answer is that both the assertion and the reason are incorrect.

### Summary of the Answer:
- Assertion: False
- Reason: False
- Therefore, the correct option is that both the assertion and reason are false.

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