Thermodynamics Questions And Answers

Q. What is the fundamental unit of enthalpy?

ML²T^-2

Q. If integration pdv and -pdv for a thermodynamic system of an ideal gas on evaluation give the same quantity during a process, then the process undergone by the system is...

Isothermal

Q. In a steam condenser the partial pressure of steam and air are 0.06 bar and 0.007 bar respectively the condenser pressure is...

0.067 bar

Q. Which law of thermodynamics will be violated, if the thermal efficiency of an engine becomes 100%

Second Law

Q. The change in enthalpy of a closed system is equal to the heat transferred, if the reversible process takes place at constant?

Pressure

I.C. Engine Questions

Q. Air standard diesel cycle a compression ratio 14 and cut off takes place at 6% of the stroke. What is the cut off ratio?

Ans. 1.78

Q. Consider the following:

1 Increased Cetane Number

2 Increased compression ratio

3 Increased injection Advance

4 Increased air Turbulence

Which of the above factors reduces physical delay in the diesel engine?

Ans. 2 and 4 only

Q. Consider the following:

Diesel engine knock can be reduced by increasing

1 Engine Speed

2 Compression Ratio

3 Degree of Supercharge

4 Injection Advance

Which of the above statement is/are correct?

Ans. 2 and 3

Q. Self ignition temp. of diesel as compare to petrol is?

Ans. Lower

Q. For a four cylinder vertical engine, the commonly used firing order is...

Ans. 1-3-4-2