Consider a hot cylindrical surface and a disk oriented

as shown in the figure. Both the cylindrical surface and

the disk behave as blackbodies. The cylinder has a

diameter D and a length L of $0\mathrm{.}2$ m $.$ The disk of

diameter D$=0\mathrm{.}2$m is placed coaxially with the

cylinder at a distance of L$=0\mathrm{.}2$m apart. The cylindrical

surface and the disk are maintained at uniform

temperatures of $1000$ K and $300$ K $,$ respectively.

Determine the rate of heat transfer by radiation from

the cylindrical surface to the disk. answer $205$W