What is the emissivity of a black body?

Related MCQs

• Emissivity of a white polished body in comparison to a black body is
• While the total emissivity of a perfect black body is unity, the same for a real body is
• Total emissivity of polished silver compared to black body is
• The total emissivity power is .defined as the total amount of radiation emitted by a black body per unit
• In thermal radiation for a black body (where, ε is emissivity and α is absorptivity)
• The wavelength at which the maximum monochromatic emissive power occurs for a black body, is (where, T = absolute temperature of the black body).
• 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is
• A body is called grey if the monochromatic emissivity of the body is
• Out of 100 kcal/second of incident radiant energy on the surface of a thermally transparent body, 300 kcal/second is reflected back. If the transmissivity of the body is 0.25, the emissivity of the surface will be
• When a body is in thermal equilibrium with its surroundings, the absorptivity and the emissivity of the body are same. This Law is known as