Assertion The average value of alternating emf is 63.39% of the peak value .
Reason The rms value of alternating emf is70.72% of peak value

Options

A. Both assertin and reason are true and reason is the correct explanation of assertion
B. Both assertion and reason are true but reason is not the correct explanation of assertion
C. Assertion is true but reason is flase
D. Both assertion and reason are false

Explanation

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

**Step 1: Analyze the Assertion**
The assertion states that the average value of alternating EMF is 63.39% of the peak value.

- The average value (E_avg) of an alternating EMF is given by the formula:
\[ E_{\text{avg}} = \frac{2E_0}{\pi} \]
where \(E_0\) is the peak value of the EMF.

- To find the percentage of the peak value, we can express it as:
\[ \frac{E_{\text{avg}}}{E_0} = \frac{2E_0/\pi}{E_0} = \frac{2}{\pi} \]
- Now, calculating \(\frac{2}{\pi}\):
\[ \frac{2}{\pi} \approx 0.6366 \text{ or } 63.66\% \]
- This is approximately equal to 63.39% when rounded.

Thus, the assertion is correct.

**Step 2: Analyze the Reason**
The reason states that the RMS value of alternating EMF is 70.72% of the peak value.

- The RMS value (E_rms) of an alternating EMF is given by the formula:
\[ E_{\text{rms}} = \frac{E_0}{\sqrt{2}} \]

- To find the percentage of the peak value, we can express it as:
\[ \frac{E_{\text{rms}}}{E_0} = \frac{E_0/\sqrt{2}}{E_0} = \frac{1}{\sqrt{2}} \]
- Now, calculating \(\frac{1}{\sqrt{2}}\):
\[ \frac{1}{\sqrt{2}} \approx 0.7071 \text{ or } 70.71\% \]
- This is approximately equal to 70.72% when rounded.

Thus, the reason is also correct.

**Step 3: Conclusion**
Both the assertion and reason are correct, but the reason does not explain the assertion. Therefore, the correct answer is that both statements are true, but the reason is not the correct explanation of the assertion.

**Final Answer:** Both the assertion and reason are correct, but the reason is not the correct explanation of the assertion.

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