In a thermodynamic process, pressure of a fixed mass of a gas is changed in such a manner that the gas molecules absorb 30 J of heat and 10 J of work is done by the gas. If the initial internal energy of the gas was 40 J, then the final internal energy will be -

(1) 30 J

(2) 20 J

(3) 60 J

(4) 40 J

First law of thermodynamics is a special case of 

(1) Newton's law

(2) Law of conservation of energy

(3) Charle's law

(4) Law of heat exchange

If the ratio of specific heat of a gas at constant pressure to that at constant volume is γ, the change in internal energy of a mass of gas, when the volume changes from V to 2V constant pressure p, is 

(1) $R/(\gamma -1)$

(2) pV

(3) $pV/(\gamma -1)$

(4) $\gamma pV/(\gamma -1)$

A monoatomic gas of n-moles is heated from temperature T₁ to T₂ under two different conditions (i) at constant volume and (ii) at constant pressure. The change in internal energy of the gas is 

(1) More for (i)

(2) More for (ii)

(3) Same in both cases

(4) Independent of number of moles

Can two isothermal curves cut each other

(1) Never

(2) Yes

(3) They will cut when temperature is 0°C

(4) Yes, when the pressure is critical pressure

A vessel containing 5 litres of a gas at 0.8 m pressure is connected to an evacuated vessel of volume 3 litres. The resultant pressure inside will be (assuming whole system to be isolated) 

(1) 4/3 m

(2) 0.5 m

(3) 2.0 m

(4) 3/4 m

If a gas is heated at constant pressure, its isothermal compressibility 

(1) Remains constant

(2) Increases linearly with temperature

(3) Decreases linearly with temperature

(4) Decreases inversely with temperature

In isothermal expansion, the pressure is determined by:

The isothermal bulk modulus of a perfect gas at normal pressure is -

(1) $1.013\times {10}^{5}N/m^2$

(2) $1.013\times {10}^{6}N/m^2$

(3) $1.013\times {10}^{-11}N/m^2$

(4) $1.013\times {10}^{11}N/m^2$