The absorptivity of a grey body at a given temperature _____________ with increasing wavelength of radiation?

Related Mcqs:

1. Absorptivity of a perfect black body is unity. Which of the following has maximum absorptivity ?

   A. Aluminium foil B. Refractory bricks C. Iron plate D. Coke breeze...

2. The statement that “maximum wavelength of radiation is inversely proportional to the temperature” is ______________ law?

   A. Stefan-Boltzmann’s B. Planck’s C. Wien’s displacement D. None of these...

3. The wavelength at which the maximum monochromatic emissive power occurs for a black body, is (where, T = absolute temperature of the black body)?

   A. αT B. α × 1/T C. α T4 D. Independent of T...

4. The ratio of total radiating power to the absorptivity of the body depends upon the _____________ as per Kirchoff‟s law?

   A. Wavelength of radiation B. Nature of the body C. Temperature of the body D. None of these...

5. The radiation heat flux from a heating element at a temperature of 800°C, in a furnace maintained at 300°C is 8 kW/m2. The flux, when the element temperature is increased to 1000°C for the same furnace temperature is_____________________?

   A. 11.2 kW/m2 B. 12.0 kW/m2 C. 14.6 kW/m2 D. 16.5 kW/m2...

6. A body is called grey if the monochromatic emissivity of the body is___________________?

   A. Zero B. Unity C. Same for all wavelengths D. Different for all wavelengths...

7. The absorptivity of a body is equal to its emissivity _________________?

   A. At a particular temperature B. For circular bodies C. Under thermal equilibrium D. None of these...

8. Absorptivity and reflectivity of a perfect black body are respectively _______________?

   A. 1 and 0 B. 0 and 1 C. 1 and ∞ D. 0 and 0.5...

9. As per Kirchoff‟s law, the ratio of the total radiating power to the absorptivity of a body depends on the_______________?

   A. Temperature of the body only B. Wavelength of monochromatic radiation C. Both A. and B. D. Nature of material of body...

10. The sum of reflectivity and absorptivity for an opaque body is equal to____________________?

    A. 0.5 B. 1 C. 0 D. 2...