Question

What is true of a blackbody? Group of answer choices It appears black to us, regardless of its temperature. Its energy is not a continuum. Its energy peaks at a wavelength determined by its temperature. If its temperature doubled, the peak in its curve would be doubled in wavelength. It has a complete absence of thermal energy.

Answer 1

The correct answer is Its energy peaks at a wavelength determined by its temperature.

Blackbody is an ideal body that absorbs all incident thermal radiation. It is, therefore, a perfect absorber, since its absorption power is equal to 1.

Although it is an idealization, there are several ways to obtain bodies with behavior similar to that of a black body. For example, we can coat any body with an irregular layer of black pigments.

As, emissivity and absorbency are equal, according to Kirchhoff's law, a black body will also have emissivity equal to 1. Thus, in addition to an ideal absorber, a black body is also an ideal emitter.