A. Absorb or emit
B. Refract
C. Reflect
D. Both B. & C.
Related Mcqs:
- 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 - A perfect black body is a perfect _____________ of radiation?
A. Absorber
B. Emitter
C. Both A. & B.
D. Neither A. nor B. - 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 - A black body when hot, emits heat radiation of _____________ wavelengths?
A. Small
B. Large
C. All
D. One fixed - The rate of emission of radiation by a body does not depend upon the__________________?
A. Wavelength of radiation
B. Surface temperature of the body
C. Nature of the surface
D. Shape and porosity of the body - 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 - 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 - 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 - 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 - 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
