A blackbody is defined as what?

A blackbody is defined as what?

• A. A perfect reflector of energy
• B. A perfect emitter and absorber of energy
• C. An object that transmits all energy
• D. An object that does not emit energy

Answer: (B)

A blackbody is an ideal object that absorbs all incident radiation and emits radiation at the maximum possible rate at every wavelength. This makes it a perfect absorber and a perfect emitter of energy. It does not reflect or transmit energy, so descriptions of it as a perfect reflector or as something that transmits energy aren’t accurate. In practice, real materials can approximate a blackbody when their surface emissivity is very close to one, meaning they absorb and emit nearly as well as an ideal blackbody.

A blackbody is an ideal object that absorbs all incident radiation and emits radiation at the maximum possible rate at every wavelength. This makes it a perfect absorber and a perfect emitter of energy. It does not reflect or transmit energy, so descriptions of it as a perfect reflector or as something that transmits energy aren’t accurate. In practice, real materials can approximate a blackbody when their surface emissivity is very close to one, meaning they absorb and emit nearly as well as an ideal blackbody.