Chemical Engineering Basics - Engineering

Q1:

For infinite parallel planes having emis-sivities ε1 & ε2, the interchange factor for radiation from surface 1 to surface 2 is given by

A1 + ε2)/ε12

B ε12/(ε1 + ε2 - ε12)

C ε12

D ε1 + ε2

ANS:B - ε12/(ε1 + ε2 - ε12)

The interchange factor for radiation from surface 1 to surface 2 between two infinite parallel planes with emissivities ε1​ and ε2​ is given by: 2F12​=ε1​+ε2​−ε1​ε2​ε1​ε2​​ Therefore, the correct choice is: ε1​+ε2​−ε1​ε2​ε1​ε2​​