WorksheetsRecall
Total questions: 5
Worksheet time: 7mins
What is emissivity?
The ability of a material to absorb heat
The ratio of radiation emitted by a surface to the radiation emitted by a perfect black body at the same temperature
The reflection of heat by a surface
The ability of a material to conduct heat
Which of the following is true about a perfect black body?
It reflects all incident radiation.
Its emissivity is 0.
It absorbs and emits radiation at all wavelengths.
It emits no radiation.
Which of the following factors does NOT affect the emissivity of a material?
Surface roughness
Material type
Temperature
The material’s thickness
How does surface roughness affect emissivity?
A rough surface usually has higher emissivity than a smooth surface.
A smooth surface always has higher emissivity than a rough surface.
Surface roughness has no effect on emissivity.
Roughness increases the reflectivity of the material.
What was the material of the Disk used in the experiment?
Copper
Aluminum
Iron
Steel
