1 Crore+ students have signed up on EduRev. Have you? 
The energy emitted (of all wavelengths) in a particular direction per unit surface area and through a unit solid angle is called
The em issive power is multiplied with the factor ................ to obtain the intensity of normal radiation for a unit surface
The earth receive at its surface radiation from the sun at the rate of 1400 W/m^{2}. The distance of the centre of sun from the surface of earth is 1.5 x 10^{11} m and the radius of the sun is 7 x 10^{8} m. Treating the sun as black body, it follows from the above data that sun's surface temperature is about
where L is mean distance between sun and earth,
r is radius of the sun
G_{s} is solar constant and equal to 1400 W/m^{2}
σ is StefanBoltzman constan
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 F_{12} for inclined parallel plates of equal width and a common edge?
What is the view factor F_{21} for the geometry having one side of a diagonal partition within a Long square duet?
By symmetry, F_{12} = F_{13} = 0.5
58 videos314 tests

Use Code STAYHOME200 and get INR 200 additional OFF

Use Coupon Code 
58 videos314 tests







