00:01
Hello, in the question we have given that two very large parallel plates are minted at uniform temperatures.
00:08
So, they have given t1 as equals to 901 k and t2 as equals to 426 k and have emissivity, emissivity, so that is epsilon 1 is equal to 0 .2 and epsilon 2.
00:33
So, the emissivity is 0 .7 respectively.
00:41
So, determine the net rate of radiation heat transfer between two surfaces per unit surface area of the plates.
00:50
So, now, first thing what we will do over here is now we can directly write the formula, but it is it is nicer to write first calculate the net emissivity.
01:05
So, the net emissivity, so the net emissivity, sorry, so we will write it as epsilon is 1 divided by 1 upon epsilon 1 plus 1 upon epsilon 2 minus 1.
01:31
So, this is the formula which we will use over here.
01:34
Now, let us plug the value.
01:35
So, we get epsilon is equal to 1 divided by so 1 divided by 1 divided by epsilon 1 epsilon 1 is 0 .2 plus 1 upon 0 .7 minus 1.
01:51
So, if we calculate this, we will get this epsilon as equals to so it should be 1 divided by 5 plus 1 .4285 minus 1...