Topic: Heat Transfer
A grey body is defined such that
- A. Monochromatic emissivity of the body is independent of temperature
- B. Monochromatic emissivity of the body is dependent of temperature
- C. Monochromatic emissivity of the body is independent of wave length
- D. Monochromatic emissivity of the body is dependent of wave length
Answer: C. Monochromatic emissivity of the body is independent of wave length
Explanation: A grey body is defined as a non-ideal radiator whose monochromatic emissivity is constant and independent of the wavelength ($\lambda$). This means it emits a constant fraction of the black body emission at all wavelengths.