KVPY SA Exam 19-Nov-2017 Question Paper

A long cylindrical pipe of radius 20 cm is closed at its upper end and has an airtight piston of negligible mass as shown. When a 50 Kg mass is attached to the other end of the pistion, it moves down by a distance $∆\mathit{l}$ before coming to equilibrium. Assuming air to be an ideal gas, $\frac{∆\mathit{l}}{\mathit{L}}$ (see figure) is close to (g = 10 ms${}^2$ , atmospheric pressure is 10${}^5$ Pascal),