Two very large parallel plates are maintained at uniform temperature of T₁= 800K and T₂= 640 K. Their emmisivities are 0.2 and 0.5 respectively. What will be the net rate of radiation heat transfer between the two surface per unit surface area of the plates? [assuming, Stefan Boltzman constant = 5.67 × 10^-8W/m²-K ;(800)⁴- (640)⁴= 2.4 × 10¹¹]

Question

Question

This question was previously asked in

BHEL Engineer Trainee Mechanical 24 Aug 2023 Official Paper

Answer 1

Concept:

The net rate of radiation heat transfer between two large parallel plates is given by:

Where:

σ = Stefan-Boltzmann constant = ,

Calculation:

Given that , substitute into the formula:

Calculate the denominator:

Now calculate the numerator:

Finally,