Test: Radiation Heat Transfer - 1 - Mechanical Engineering MCQ

What combination of surface characteristics is required for solar collectors?

The radiant heat exchange between two bodies depends upon
1. how they see each other
2. their emitting and absorbing characteristics and
3. the medium that intervenes the two bodies 

Which of the above statements are valid?

Consider the following statements pertaining to emissivity:

1. A gray body has variable monochromatic em issivity, ∈_λ, with respect to wavelength .
2. A gray body has a characteristic emissivity value of less than unity which does not vary with temperature.
3. According to kirchoff’s law, the emissivity of the surface of a body is equal to its absorptivity when the body is in thermal equilibrium with its surroundings,
4. Kirchoff’s law holds good for monochromatic radiation.

Which of the above statements are valid?

For the same type of shapes , the value of radiation shape factor will be higher when

What is the value of shape factor for two infinite* parallel surfaces separated by a distance x?

What is the view factor F₁₂ for inclined parallel plates of equal width and a common edge?

What is the view factor F₂₁ for the geometry having one side of a diagonal partition within a Long square duet?