Question

A cylinder containing an ideal gas is in vertical position, and has a piston of mass M, that is able to move up or down without friction as shown in Fig. If the temperature of gas inside cylinder is increased, then

(1) Both P and V of the gas will change

(2) Only P will increase according to Charle’s law

(3) V will change but not P.

(4) P will change but not V

Answer 1

(3) V will change but not P.

P = The total pressure on gas in cylinder 

= Atmospheric pressure + pressure due to mass of piston

where A = area of cross–section of piston.

As the temperature is increased, only the volume increases in accordance with Charle’s law as the piston moves up without friction.