Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Kinetic Theory

Question:

Two cylinders fitted with pistons and placed as shown, connected with string through a small tube of negligible volume, are filled with a gas at pressure Po and temperature To. The radius of smaller cylinder is half of the other. If the temperature is increased tp 2To, find the pressure, if the piston of bigger cylinder moves towards left by 1 meter ?

image

Options:

\(\frac{4}{5}P_o\)

\(\frac{3}{5}P_o\)

\(\frac{2}{5}P_o\)

\(\frac{5}{4}P_o\)

Correct Answer:

\(\frac{5}{4}P_o\)

Explanation:

Initial volume = 1 x [\(\pi R^2 + \frac{\pi R^2}{4}\)] = \(\frac{5}{4}\pi R62\)

Piston moves towards left by 1 m on heating. Additional volume available due to heating is :

  = 1 x \(\pi R^2\) - \(\frac{1*\pi R^2}{4}\) = \(\frac{3}{4} \pi R^2\)

Total volume after heating = 2 \(\pi R^2\)

\(P_o*\frac{5}{4}\pi R^2 = nRT_o\)

After heating : \(P_2 * 2\pi R^2 = nR * 2T_o\)

\(\frac{P_1}{P_2} \frac{5}{4} \frac{1}{2} = \frac{1}{2}\)

\(P_2 = \frac{5P_o}{4}\)