Emissivity MCQs : Here you will find MCQ Questions related to "Emissivity" in Mass Transfer. These Emissivity MCQ Questions Will help you to improve your Mass Transfer knowledge and will prepare you for various Examinations like Competitive Exams, Placements, Interviews and other Entrance Exmaniations
Question 1
The ___________ of the surface of a material is its effectiveness in emitting energy as thermal radiation.
A. Concentrations
B. Drying
C. Emissivity
D. Fluxes
Question 2
Emissivity ratio varies from?
A. 0 to 10
B. 0 to 1
C. 0 to 0.1
D. 0.1 to 1
Question 3
The surface of a perfect black body (with an emissivity of 1) emits thermal radiation at the rate of approximately ___________ watts per square metre
A. 100
B. 235
C. 338
D. 448
Question 4
Pyrometers and infrared cameras are instruments used to measure the temperature of an object by using its thermal radiation.
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
Question 5
Paint has Emissivity of?
A. 0.6
B. 0.7
C. 0.8
D. 0.9
Question 6
Which one is having highest emissivity?
A. Polished aluminum
B. Aluminum foil
C. Tarnished copper
D. Polished copper
Question 7
Aluminium foil has Emissivity of?
A. 0.01
B. 0.02
C. 0.03
D. 0.04
Question 8
Which one is having the lowest emissivity?
A. White marble
B. Polished stainless steel
C. Asphalt
D. Snow
Question 9
What is the value of emissivity for asphalt?
A. 0.9
B. 0.55
C. 0.85
D. 0.65
Question 10
solar heat collectors gain heat by emitting thermal radiation
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say