A perfect black body is a perfect _____________ of radiation?

Related Mcqs:

1. While the total emissivity of a perfect black body is unity, the same for a real body is__________________?

   A. 0 B. 1 C. > 1 D. Between 0 and 1...

2. A black body when hot, emits heat radiation of _____________ wavelengths?

   A. Small B. Large C. All D. One fixed...

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. 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...

5. 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...

6. A black body does not ____________ radiation?

   A. Absorb or emit B. Refract C. Reflect D. Both B. & C....

7. Which one gives the monochromatic emissive power for black body radiation ?

   A. Planck’s law B. Kirchhoff’s law C. Wien’s law D. Stefan-Boltzmann law...

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

   A. Increases B. Decreases C. Remain constant D. May increase or decrease; depends on the material...

9. The thermal radiation emitted by a body is proportional to Tn, where T is its absolute temperature. The value of ‘n’ is exactly 4 for__________________?

   A. Black painted bodies only B. All bodies C. Polished bodies only D. A black body...

10. Radiant energy received by a body is proportional to (where, d = the distance between the object emitting radiation and that receiving it.) ?

    A. √d B. d C. d2 D. d1.5...