If a third rectangular plate, with both surfaces having an emissivity of 0.8 is placed between the two plates described
in Problem 23.31, how will the answer to part (a) of the problem be affected? Draw the thermal circuit for this case.

Data From Problem 23.31

Two parallel rectangles have emissivities of 0.6 and 0.9, respectively. These rectangles are 1.2 m wide and 2.4 m high and are 0.6 m apart. The plate having ε = 0.6 is maintained at 1000 K and the other is at 420 K. The surroundings may be considered to absorb all energy that escapes the two-plate
system.