Difference Between Black Body and Grey Body

black body is an object that absorbs all the radiant energy reaching its surface with all the wavelengths. WHILE A gray body is defined as a body whose absorption does not change with variation in temperature & wavelength of the incident radiation.

1. What is the GREY body?
2. What is the Colour of black body?
3. What is meant by a black body?
4. What does a black body look like?
5. What is a gray body Mcq?
6. What is the emissivity of a black body?
7. Is human body a black body?
8. Why Sun is a black body?
9. What is the temperature of a black body?
10. What is the black body in chemistry?
11. Is snow a black body justify?
12. What is Ferry's black body?

What is the GREY body?

A gray body is an imperfect black body; i.e., a physical object that partially absorbs incident electromagnetic radiation. The ratio of a gray body's thermal radiation to a black body's thermal radiation at the same temperature is called the emissivity of the gray body.

What is the Colour of black body?

A black-body appears black at room temperature. Again most of the energy it radiates is in the form of an infra-red ray. A black body's infrared ray radiation cannot be perceived by the human eyes as the human eyes never perceive color at very low intensities of light.

What is meant by a black body?

Blackbody, also spelled black body, in physics, a surface that absorbs all radiant energy falling on it. The term arises because incident visible light will be absorbed rather than reflected, and therefore the surface will appear black.

What does a black body look like?

A black body would look black, ie no light reflection. Your eyes see no photons as black. A more interesting question is how did studying black bodies lead to Plank's constant h. A black body would only look black if it were cold.

What is a gray body Mcq?

a body of which the monochromatic emissivity (ε) is constant for the entire wavelength spectrum.

What is the emissivity of a black body?

A blackbody has an emissivity of 1, while a perfect reflector or whitebody has an emissivity of 0. Most natural objects are considered "graybodies" as they emit a fraction of their maximum possible blackbody radiation at a given temperature.

Is human body a black body?

According to Wien's law, this corresponds to a surface temperature of about 10,000 degrees Fahrenheit. Similarly, a human body temperature of 98.6 degrees Fahrenheit corresponds to a blackbody radiation frequency of about 32 terahertz, which is in the infrared part of the spectrum.

Why Sun is a black body?

The term originates because for a blackbody all visible light will be absorbed rather than reflected, and therefore the surface will appear black. A star, like the Sun is a near perfect blackbody. A blackbody does not reflect any light, nor does it allow any light to pass through (transmit).

What is the temperature of a black body?

The black body temperature of the Earth is -23°C, but the actual surface temperature is about 15°C. The difference (38°C) is the amount by which the planet is warmed by the absorption of radiation within its atmosphere, by the natural greenhouse effect.

What is the black body in chemistry?

A black-body is an ideal object that emits all frequencies of radiation with a spectral distribution that depends only on the temperature and not on its composition. The radiation emitted by such an object is called black-body radiation.

Is snow a black body justify?

In contrast to radiation in the visible bands of light, long-wave radiation (> 3mm) is almost perfectly absorbed by the snow. Hence, snow is nearly a "black body" for long wave radiation. Snow reflectance also varies with the grain size of snow.

What is Ferry's black body?

A cavity with walls made of any material, with a small opening, is an excellent black body. This is Ferry's black body. It also absorbs all electromagnetic radiation incident on it irrespective of wavelength.