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WorksheetsRadiation Basic Concepts
Total questions: 14
Worksheet time: 13mins
If the reflectivity of an opaque surface is 0.6, then emissivity of that surface will be
0
1
0.6
0.4
can't be determined
Stefan Boltzmann Law estimate
spectral emissive power of any body
hemispherical emissive power of any body
total hemispherical emissive power of any body
None of these are correct
A light bulb of filament temperature 2400K will emit maximum power at which wavelength. This problem can be solved by
Plank's Law
Stefan Boltzmann Law
Wein Law
Kirchoff's law
reflectivity of a black body is
0
1
between 0 and 1
None of these
For a black body
Radiosity =Emissive power
Radiosity< Emissive power
Radiosity> Emissive power
There is no relation between Radiosity & Emissive power
For a gray surface
radiation properties are independent of wave length
radiation properties are independent of direction
emissivity =absorptivity=1
emissivity is not equal to absorptivity
Radiation properties can be changed by a thin coating on them
True
False
A black body is a diffuse emitter
True
False
Value of Stefan Boltzmann Constant in SI unit is
5.87×108
5.67×108
7.65×108
None of these
Emissivity of concrete is close to
0
1
emissivity of polished steel is close to
0
1
Infrared range of thermal radiation mostly absorved by
oxygen
carbon dioxide & water vapor
Ozone
Earth atmosphere only absorb solar radiation but not emit radiation
True
False
Higher energy contained in
Microwaves, radio waves having large wave length
X-Rays, Y-Rays with small wavelength
