The view factors F12 and F21, for the sphere of diameter d and a cubical box of length l = d as shown in the figure, respectively, are
1
\(1\;and\frac{\pi }{3}\)
2
\(\frac{\pi }{3}and\;1\)
3
\(1\;and\;\frac{\pi }{6}\)
4
\(\frac{\pi }{6}and\;1\)
The view factors F12 and F21, for the sphere of diameter d and a cubical box of length l = d as shown in the figure, respectively, are