Heat Transfer MCQ’s – Solar Absorptivity
1 - Question
Which one is having the highest value of solar absorptivity?
a) White marble
b) Concrete
c) Asphalt
d) Snow
View Answer
Explanation: Solar absorptivity for asphalt is 0.90 while that of white marble, concrete and snow are 0.46, 0.60 and 0.28 respectively.
2 - Question
What is the value of solar absorptivity for aluminum foil?
a) 0.15
b) 0.16
c) 0.17
d) 0.18
View Answer
Explanation: Solar absorptivity doesn’t require a medium and for aluminum, it reaches maximum efficiency in a vacuum.
3 - Question
What is the value of solar absorptivity for polished copper?
a) 0.17
b) 0.18
c) 0.19
d) 0.20
View Answer
Explanation: Solar absorptivity for polished copper depends on the frequency and wavelength of the radiation.
4 - Question
Which one is having the lowest value of solar absorptivity?
a) Snow
b) Red brick
c) Aluminum foil
d) Polished aluminum
View Answer
Explanation: Solar absorptivity for polished aluminum is 0.09 while that of red brick, aluminum foil and snow are 0.63, 0.15 and 0.28 respectively.
5 - Question
What is the value of solar absorptivity for polished stainless steel?
a) 0.37
b) 0.36
c) 0.35
d) 0.34
View Answer
Explanation: There is vibration within the molecules and it can potentially initiate electromagnetic waves.
6 - Question
Which one is having the lowest value of solar absorptivity?
a) Black paint
b) Dull stainless steel
c) Concrete
d) White marble
View Answer
Explanation: Solar absorptivity for white marble is 0.46 while that of black paint, dull stainless steel and concrete are 0.97, 0.50 and 0.60 respectively
7 - Question
What is the value of solar absorptivity for white marble?
a) 0.45
b) 0.46
c) 0.47
d) 0.48
View Answer
Explanation: It generates and receives electromagnetic waves at the expense of its stored energy.
8 - Question
Which one is having the highest value of solar absorptivity?
a) Red brick
b) Asphalt
c) Black paint
d) White paint
View Answer
Explanation: Emissivity of black paint is 0.97 while that of red brick, asphalt and white paint are 0.63, 0.90 and 0.14 respectively.
9 - Question
What is the value of solar absorptivity for asphalt?
a) 0.90
b) 0.80
c) 0.70
d) 0.60
View Answer
Explanation: Energy emitted by asphalt is not continuous but is in the form of quanta.
10 - Question
What is the value of solar absorptivity for snow?
a) 0.25
b) 0.26
c) 0.27
d) 0.28
View Answer
Explanation: Solar absorptivity for snow varies on the nature of its surface and its temperature.