Engineering Thermodynamics MCQs

Question 1

The compression ratio for petrol engines is

Accepted Answer

5 to 8

Answer

3 to 6

Answer

10 to 20

Answer

15 to 30

Question 2

Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant

Accepted Answer

Pressure

Answer

Temperature

Answer

Volume

Answer

Internal energy

Question 3

Change in internal energy in a closed system is equal to heat transferred if the reversible process takes place at constant

Accepted Answer

Volume

Answer

Pressure

Answer

Temperature

Answer

Internal energy

Question 4

A definite area or a space where some thermodynamic process takes place is known as

Accepted Answer

Thermodynamic system

Answer

Thermodynamic cycle

Answer

Thermodynamic process

Answer

Thermodynamic law

Question 5

The work ratio of a gas turbine plant is given by

Accepted Answer

$$\frac{{{	ext{Net work output}}}}{{{	ext{Work done by the turbine}}}}$$

Answer

$$\frac{{{	ext{Net work output}}}}{{{	ext{Heat supplied}}}}$$

Answer

$$\frac{{{	ext{Actual temperature drop}}}}{{{	ext{Isentropic temperature drop}}}}$$

Answer

$$\frac{{{	ext{Isentropic increase in temperature}}}}{{{	ext{Actual increase in temperature}}}}$$

Question 6

The mass of excess air supplied is equal to

Accepted Answer

$$\frac{{100}}{{23}}$$ × Mass of excess oxygen

Answer

$$\frac{{23}}{{100}}$$ × Mass of excess carbon

Answer

$$\frac{{23}}{{100}}$$ × Mass of excess oxygen

Answer

$$\frac{{100}}{{23}}$$ × Mass of excess carbon

Question 7

An ideal gas as compared to a real gas at very high pressure occupies

Accepted Answer

More volume

Answer

Less volume

Answer

Same volume

Answer

Unpredictable behavior

Question 8

The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and re-condensed, then the liquid with the next higher boiling point is then evaporated and re-condensed, and so on until all the available liquid fuels are separately recovered in the sequence of their boiling points. Such a process is called

Accepted Answer

Fractional distillation

Answer

Cracking

Answer

Full distillation

Answer

Carbonisation

Question 9

If the value of n = 0 in the equation pvn = C, then the process is called

Accepted Answer

Constant pressure process

Answer

Constant volume process

Answer

Adiabatic process

Answer

Isothermal process