The diameter of the mercury barometer tube is recorded as 6 mm. How much error is introduced due to surface tension in this reading. Surface tension of mercury is `540 xx 10^(-3)" N/m"` Angle of contact for mercury is `140^@`.

Explanation

To find the error introduced due to surface tension in the reading of a mercury barometer tube, we can follow these steps:

### Step 1: Understand the Formula for Depression in Mercury
The depression in the mercury level in the barometer due to surface tension can be calculated using the formula:

\[ H = \frac{2T \cos \theta}{R \rho g} \]
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