Heat transfer through radiation takes place in form of:
Two spheres A and B of same material have radius 1 m and 4 m, and temperatures 4000 K and 2000 K respectively. Then the energy radiated by sphere A is
For a glass plate transmissivity and reflectivity are specified as 0.76 and 0.08 respectively, the absorptivity of the glass plate is ___________.
The total emissive power of a surface is 500 W/m2 at a temperature T1 and 1200 W/m2 at a temperature T2, where the temperatures are in Kelvin Assuming the emissivity of the surface to be constant, the ratio of the temperatures is
The peak wavelength of radiation emitted by a black body at a temperature of 2000 K is 1.45 μm. If the peak wavelength of emitted radiation changes to 2.90 μm, then the temperature (in K) of the black body is___.
The number of radiation shield screens in case of radiation heat transfer to reduce the radiation heat exchange by 80% is __________.
A solid sphere 1 of radius ‘r’ is placed inside a hollow, closed hemispherical surface 2 of radius ‘4r’. The shape factor F2-1 is
The temperature of solid surface changes from 27 °C to 627 °C. The emissive power changes would then confirm to the ratio ________.
Consider the radiation heat exchange inside an annulus between two very long concentric cylinders. The radius of the outer cylinder is R0 and that of the inner cylinder is Ri. The radiation view factor of the outer cylinder onto itself is
For a diffused body, emissivity is given as 0.5 and emissive power of the black body is given as 20W/m2. Calculate the intensity of radiation of body? (in W/m2)