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A perfect black body is

A perfect black body is Correct Answer One which absorbs all radiant energy at all wavelengths

Explanation:

Black body

  • A black body is an object that absorbs all the radiant energy reaching its surface.
  • No actual body is perfectly black; the concept of a black body is an idealization with which the radiation characteristics of real bodies can be compared.
     

Properties of the black body:

  • It absorbs all the incident radiation falling on it and does not transmit or reflect regardless of wavelength and direction
  • It emits the maximum amount of thermal radiation at all wavelengths at any specified temperature
  • It is a diffuser emitter (i.e. the radiation emitted by a black body is independent of direction)
  • Transparent body: τ = 1, α = ρ = 0
  • Opaque body: τ = 0

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