Assertion: On moon, barometer height will be six times compared to the height on earth.
Reason: Value of g on moon's surface is 1/6 the value of g on earth's surface.

Options

A. (a) If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
B. (b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
C. (c) If Assertion is true, but the Reason is false.
D. (d) If Assertion is false but the Reason is true.

Explanation

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

### Step 1: Understand the Assertion
The assertion states that "On the moon, barometer height will be six times compared to the height on Earth." A barometer measures atmospheric pressure, which is related to the height of the mercury column in the barometer.

### Step 2: Analyze the Reason
The reason given is that "Value of g on the moon's surface is 1/6 the value of g on Earth's surface." This means that the gravitational acceleration on the moon is significantly less than that on Earth.

### Step 3: Evaluate the Conditions on the Moon
The moon has a very thin atmosphere, which is almost negligible. In fact, the moon does not have a substantial atmosphere at all. This lack of atmosphere means that a barometer, which relies on atmospheric pressure to function, would not work on the moon.

### Step 4: Conclusion on the Assertion
Since a barometer requires atmospheric pressure to measure the height of the mercury column, and there is virtually no atmosphere on the moon, the assertion that the barometer height will be six times that on Earth is false.

### Step 5: Conclusion on the Reason
The reason is true; the value of g on the moon is indeed 1/6 that of Earth. However, this does not support the assertion because the assertion is based on the existence of atmospheric pressure, which is not present on the moon.

### Final Evaluation
- The assertion is false because a barometer cannot function on the moon due to the lack of atmosphere.
- The reason is true as the gravitational acceleration on the moon is indeed 1/6 of that on Earth.

Therefore, the correct answer is:
**Option D: Assertion is false but reason is true.**

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