Final answer:
The value of the view factor for two inclined flat plates with a common edge and an angle of 20 degrees is approximately 0.766 (option a).
Step-by-step explanation:
The view factor, also known as the shape factor, represents the fraction of energy emitted by one surface that is absorbed by another surface.
For two inclined flat plates with a common edge and an angle of 20 degrees, the view factor can be calculated using the formula:
F = (cos α1 + cos α2) / (2π)
where α1 and α2 are the angles of each plate with respect to the normal to the common edge. In this case, both plates have an angle of 20 degrees, so we can substitute α1 = α2 = 20 degrees into the formula:
F = (cos 20 + cos 20) / (2π)
F ≈ 0.766
Therefore, the value of the view factor for these inclined flat plates is approximately 0.766 (option a).