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

Related Mcqs:

1. 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

2. 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

3. A black body does not ____________ radiation?

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

4. A perfect black body is a perfect _____________ of radiation?

   A. Absorber
   B. Emitter
   C. Both A. & B.
   D. Neither A. nor B.

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

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

6. “The ratio of the total emissive power to the absorptivity for all bodies is same at ther-mal equilibrium”. This is ______________ law?

   A. Kirchoff’s
   B. Planck’s
   C. Wien’s displacement
   D. Stefan-Boltzmann

7. 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

8. Stefan’s block body radiation law can also be derived from ______________ law?

   A. Kirchoff’s
   B. Planck’s
   C. Fourier’s
   D. None of these

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