Question
Question: The absorptivity of Lamp black is A. 0.91 B. 0.98 C. 1.00 D. 0.99...
The absorptivity of Lamp black is
A. 0.91
B. 0.98
C. 1.00
D. 0.99
Solution
It is known that in science, absorptivity may refer to molar absorptivity, in chemistry, a measurement of how strongly a chemical species absorbs light at a given wavelength. Absorptance, in physics, the fraction of radiation absorbed at a given wavelength. A body at temperature T radiates electromagnetic energy. For an arbitrary body emitting and absorbing thermal radiation in thermodynamic equilibrium, the emissivity is equal to the absorptivity. Large variations in temperature can cause a variation in emissivity. The emissivity of metals tends to increase as the temperature increases. The emissivity of non-metals tends to decrease as the temperature increases.
Complete step by step answer:
We know that black body is a body which absorbs and emits all types of radiations completely. Since we know that lamp black is a perfect black body so it absorbs 100% of all incoming photons.
With this we can conclude that the absorptivity of Lamp black is 1.00.
Therefore, the correct answer is Option C.
Note: Thus, we can conclude that because the light is outside the range of human vision, it is invisible, so a room illuminated with a black light appears dark. There are many types of black lights, including special fluorescent lamps, LEDs, incandescent lamps, and lasers. These lights are not created equal, as each produces a unique spectrum of light. Strong sources of long-wave ultraviolet light are used in tanning beds. Although the low-power UV-A emitted by black lights is not a hazard to skin or eyes and can be viewed without protection, powerful ultraviolet sources present dangers and require personal protective equipment such as goggles and gloves.