A. √d
B. d
C. d2
D. d1.5
Related Mcqs:
- With increase in the distance between the heat source and the object receiving the heat, the radiation heat transfer ?
A. Decreases
B. Increases
C. Increases exponentially
D. Remain unaffected - 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_________________?
A. 0.35
B. 0.45
C. 0.55
D. 0.85 - 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 - Stefan-Boltzmann law which describes the radiation heat transfer states that, it is proportional to (where, t = temperature in °C T = absolute temperature in ° K) ?
A. t4
B. T4
C. 1/t4
D. 1/T4 - 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 - Radiation energy is emitted by all the substances, which are above____________________?
A. 0°K
B. 0°C
C. 100°C
D. Room temperature - 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 - A black body does not ____________ radiation?
A. Absorb or emit
B. Refract
C. Reflect
D. Both B. & C. - 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 - 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
