Properties of Pure Substances - Mechanical Engineering (MCQ) questions and answers

1)   What is the saturated solid state?

a. a state at which solid can change into liquid at constant pressure but changing temperature
b. a state at which solid can change into liquid at constant temperature but change in pressure
c. a state at which solid can change into liquid at constant pressure and temperature
d. none of the above
Answer  Explanation 

ANSWER: a state at which solid can change into liquid at constant pressure and temperature

Explanation:
No explanation is available for this question!


2)   What is a liquid, whose temperature is less than the saturation temperature at the given pressure, called?

a. compressed liquid
b. subcooled liquid
c. both a. and b.
d. none of the above
Answer  Explanation 

ANSWER: both a. and b.

Explanation:
No explanation is available for this question!


3)   What is the degree of subcooling?

a. the difference between saturation temperature of liquid and actual temperature of liquid
b. the difference between saturation temperature of vapour and actual temperature of liquid
c. the difference between saturation temperature of liquid and actual temperature of vapour
d. the difference between saturation temperature of vapour and actual temperature of vapour
Answer  Explanation 

ANSWER: the difference between saturation temperature of liquid and actual temperature of liquid

Explanation:
No explanation is available for this question!


4)   The dryness (x) fraction of superheated steam is taken as

a. x= 0
b. x= 0.9
c. x= 0.999
d. x= 1
Answer  Explanation 

ANSWER: x= 1

Explanation:
No explanation is available for this question!


5)   What is the line which starts from critical point having constant dryness fraction throughout the line as shown in figure (Line1) called?

a. constant vapour line
b. constant liquid line
c. constant quality line
d. none of the above
Answer  Explanation 

ANSWER: constant quality line

Explanation:
No explanation is available for this question!


6)   What is the dryness fraction (x) on saturated vapour line?

a. x = 0
b. x = 1
c. x = 0.9
d. x = 0.5
Answer  Explanation 

ANSWER: x = 1

Explanation:
No explanation is available for this question!


7)   What is the dryness fraction (x) for saturated water, when water just starts boiling?

a. x = 0
b. x = 1
c. x = 0.9
d. x = 0.5
Answer  Explanation 

ANSWER: x = 0

Explanation:
No explanation is available for this question!


8)   If m1 and m2 are the masses of liquid and vapour respectively in a liquid-vapour mixture, then what is the formula for dryness fraction x?

a. x = (m1 + m2) / m1
b. x = (m1 + m2) / m2
c. x = m1 / (m1 + m2)
d. x = m2 / (m1 + m2)
Answer  Explanation 

ANSWER: x = m2 / (m1 + m2)

Explanation:
No explanation is available for this question!


9)   The temperature at which a pure liquid transforms into vapour at constant pressure is called as

a. vaporisation temperature
b. normal temperature
c. saturation temperature
d. none of the above
Answer  Explanation 

ANSWER: saturation temperature

Explanation:
No explanation is available for this question!


10)   The temperature of a substance at which the vapour pressure is equal to 760 mm Hg is called as

a. normal vapour point
b. normal boiling point
c. normal pressure point
d. none of the above
Answer  Explanation 

ANSWER: normal boiling point

Explanation:
No explanation is available for this question!


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