Question 5.C-A.60: In a faulty barometer, some inert gas is entrapped above the...

(i) Part I: Find the length of the Hg column and entrapped gas in a one metre tube from the given data. Find the volume of entrapped gas (V_{1}) .

Then atmospheric pressure, (P_{a}) = Pressure due to entrapped air (P_{1}) + Pressure due to ‘x’cm of Hg column              (1)

Part II: When a test tube is pulled out by 10 cm from the trough, find the length of the air column. Find the volume of the entrapped gas (V_{2}).

Now, P_{a} = Pressure due to ‘x’ cm of Hg column + pressure due to entrapped air (P_{2})                              (2)

From Boyle’s law

P_{1} V_{1}=P_{2} V_{2}                             (3)

Substitute the values of P_{1} and P_{2} that are obtained in (1) and (2) into (3).

Solve the equation thus obtained to get the value of ‘P_{a}’.

(ii) 75 cm of Hg.