The entropy change in a reversible isothermal process, when an ideal gas expands to four times its initial volume is_________________?

Related Mcqs:

1. On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line (∂P/∂V)T are related as (where, y = Cp/Cv) ?

   A. (∂P/∂V)S = (∂P/∂V)T
   B. (∂P/∂V)S = [(∂P/∂V)T]Y
   C. (∂P/∂V)S = y(∂P/∂V)T
   D. (∂P/∂V)S = 1/y(∂P/∂V)T

2. During a reversible isothermal expansion of an ideal gas, the entropy change is_________________?

   A. +ve
   B. 0
   C. -ve
   D. ∞

3. 1m3 of an ideal gas at 500 K and 1000 kPa expands reversibly to 5 times its initial volume in an insulated container. If the specific heat capacity (at constant pressure) of the gas is 21 J/mole . K, the final temperature will be ?

   A. 35 K
   B. 174 K
   C. 274 K
   D. 154 K

4. A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then (where, Δ S1 and Δ SR are the entropy changes of the system for the irreversible and reversible processes respectively) ?

   A. Δ S1 is always Δ SR
   C. Δ S1 is always > Δ SR
   D. Δ S1 is always = Δ SR

5. During a reversible isothermal expansion of an ideal gas, the entropy change is___________________?

   A. +ve
   B. 0
   C. -ve
   D. ∞

6. The compressibility factor of a gas is given by (where, V1 = actual volume of the gas V2 = gas volume predicted by ideal gas law)____________________?

   A. V1/V2
   B. V2/V1
   C. V1 – V2
   D. V1.V2

7. Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400°C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg. K, entropy of saturated vapour = 7.2234 kJ/kg. K) The exit condition of steam is_______________?

   A. Superheated vapour
   B. Partially condensed vapour with quality of 0.9
   C. Saturated vapour
   D. Partially condensed vapour with quality of 0.1

8. 4 kg moles of an ideal gas expands in vacuum spontaneously. The work done is_________________?

   A. 4 J
   B. ∞
   C. 0
   D. 8 J

9. In an isothermal process on an ideal gas, the pressure increases by 0.5 percent. The volume decreases by about _____________ percent?

   A. 0.25
   B. 0.5
   C. 0.75
   D. 1

10. A two stage compressor is used to compress an ideal gas. The gas is cooled to the initial temperature after each stage. The intermediate pressure for the minimum total work requirement should be equal to the _____________ mean of P1 and P2.(where, P1 and P2 are initial and final pressures respectively) ?

    A. Logarithmic
    B. Arithmetic
    C. Geometric
    D. Harmonic