An ideal gas enclosed in a vertical cylindrical container supports a freely moving piston of mass M. The piston and cylinder have equal cross sectional area A. When the piston is in equilibrium, the volume of the gas is V0 and its pressure is P0. The piston is slightly displaced from the equilibrium position and released. Assuming that the system is completely isolated from its surrounding, the piston executes a simple harmonic motion with frequency
C.
FBD of piston at equilibrium
⇒ Patm A + mg = P0A
FBD of piston when piston is pushed down a distance x
Three perfect gases at absolute temperature T1, T2 and T3 are mixed. The masses of molecules are m1,m2 and m3 and the number of molecules is n1,n2 and n3 respectively.Assuming no loss of energy, the final temperature of the mixture is
A.
For adiabatic process i.e., no heat change
A Carnot engine operating between temperatures T1 and T2 has efficiency 1/6. When T2 is lowered by 62 K, its efficiency increases to 1/3. Then T1 and T2 are, respectively
372 K and 330 K
330 K and 268 K
310 K and 248 K
310 K and 248 K
D.
310 K and 248 K
The efficiency is given by,
Helium gas goes through a cycle ABCDA (consisting of two isochoric and two isobaric lines) as shown in the figure. Efficiency of this cycle is nearly:(Assume the gas to be close to ideal gas)
15.4%
9.1%
10.5%
10.5%
A.
15.4%
The efficiency of a process is defined as the ratio of work done to energy supplied.
Here,
Where Cp and Cv are two heat capacities (molar)
A Carnot engine, whose efficiency is 40%, takes in heat from a source maintained at a temperature of 500 K It is desired to have an engine of efficiency 60%. Then, the intake temperature for the same exhaust (sink) temperature must be
the efficiency of Carnot engine cannot be made larger than 50%
1200 K
750 K
750 K
C.
750 K
Efficiency