Question

The absorptivity of Lamp black is
A. 0.91
B. 0.98
C. 1.00
D. 0.99

Answer 1

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.