Mechanical Engineering Mcqs Practice Test

Question 1

The increase in pressure _________________?

Accepted Answer

B. raises the boiling point of a liquid

Question 2

Equivalent evaporation of water is the evaporation “for a feed water supply at 100°C__________________?

Accepted Answer

A. and its corresponding conversion into dry saturated steam at 100°C and 1.033 kg/cm2

Question 3

Water boils when its vapour pressure ___________________?

Accepted Answer

A. equals that of the surroundings

Question 4

The state of vapour under saturation condition is described by_______________?

Accepted Answer

D. pressure and dryness fraction

Question 5

Heating wet steam at constant temperature is heating it at constant_________________?

Accepted Answer

B. pressure

Question 6

In an experiment to determine dryness fraction of steam, the mass of water separated was 1.2 kg in 15 mts and the mass of steam passed out in same time was 4.8 kg. Dryness fraction is__________________?

Accepted Answer

D. 80%

Question 7

At critical point, i.e. p=225.65 kg/cm2, the latent enthalpy of vaporisation is______________?

Accepted Answer

C. zero

Question 8

Latent heat of dry steam at atmospneric pressure is equal to____________________?

Accepted Answer

A. 539 kcal/kg

Question 9

In a throttling process_________________?

Accepted Answer

E. none of the above

Question 10

The dry saturated steam at very high pressure (150-200 kg/cm2) when throttled to atmosphere will become_______________?

Accepted Answer

A. wet

Question 11

The dry saturated steam at very low pressure, (5-10 kg/cm2) when throttled to atmosphere will become________________?

Accepted Answer

B. superheated

Question 12

On Mollier chart, free expansion, or throttling process from high pressure to atmosphere is represented by_______________?

Accepted Answer

A. horizontal straight line

Question 13

A wet vapour can be completely specified by__________________?

Accepted Answer

E. pressure and dryness fraction

Question 14

The specific heat of superheated steam in kcal/kg is generally of the order of___________________?

Accepted Answer

C. 0.5

Question 15

One kg of steam sample contains 0.8 kg dry steam; it’s dryness fraction is__________________?

Accepted Answer

B. 0.8

Question 16

Sublimation region is the region where__________________?

Accepted Answer

A. solid and vapour phases are in equi-librium

Question 17

The equivalent evaporation of a boiler is a measure to compare _________________?

Accepted Answer

E. any type of boilers operating under any conditions

Question 18

Equivalent evaporation is the amount of water evaporated in a boiler from and at ____________________?

Accepted Answer

B. 100°C

Question 19

1 kg.m is equal to_________________?

Accepted Answer

A. 9.81 Joules

Question 20

Coke is produced by__________________?

Accepted Answer

C. strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel