Test on Thermodynamics

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 energy of efficiency 60%. Then, the intake temperature for the same exhaust (sink) temperature must be

When a system is taken from state i to state f along the path iaf, it is found that Q = 50 cal and W = 20 cal. Along the path ibf Q = 36 cal. W along path ibf (in cal) is

Helium gas goes through a cycle ABCDA (consisting of two isochoric and two isobaric lines) as shown in figure. Efficiency of this cycle is nearly (Assume the gas to be close to ideal gas)

An ideal gas undergoes a quasi static reversible process in which its molar heat capacity C remains constant. If during this process the relation of pressure P and volume V is given by constant, then n is given by (Here C_p and C_V are molar specific heat at constant pressure and constant volume, respectively):

“Heat cannot by itself flow from a body at lower temperature to a body at higher temperature” is a statement of consequence of