# Interview Questions on Thermodynamics

Questions and answers on thermodynamics topic from 11 to 20.

11. What is the name given to the ratio of actual cycle efficiency and ideal cycle efficiency?
Efficiency ratio.
12. For same compression ratio, whether Otto cycle or Diesel cycle is more efficient ?
Otto cycle is more efficient than diesel cycle.
13. If cut off ratio of diesel cycle is increased, what happens to its efficiency ?
It decreases.
14. How the network to drive a compressor and its volumetric efficiency behave with increase in clearance volume?
Work remains unaltered and volumetric efficiency decreases.
15. Why axial flow compressor is preferred in aircraft gas turbines ?
It has low frontal area.
16. How does ratio Cp / Cv behave with increase in temperature ?
It decreases.
17. Which machine will produce continuous work without receiving any energy from other system or surroundings?
18. What are the similarities between heat and work ?
Both heat and work are transient phenomena, i.e. these cross the boundaries of the system whenever system undergoes a change of state.
Both heat and work are observed at boundaries of the system.
Both are path functions and are inexact differentials.
19. Under what conditions ∫ p. dv represents the work ?
∫ p.dv represents work, when the system is closed, and the process takes place in the non-flow system; the process is quasi-static, and the boundary of the system moves so that work may be transferred.
20. What is the definition of 1 Kelvin as per internationally accepted temperature scale ?
1 Kelvin = 1/273.16 the of the triple point of water.

1 2 3