Heat TransferMedium
Question
The radiation from the sun, Incident normally at the surdace of the earth is 20 kcal/m2 min.What would have the radiant energy incident normally on earth if the sun had a temperature, Twice of the preasent one ?
Options
A.80 kcal/m2 min
B.320 kcal/m2 min
C.160 kcal/m2 min
D.40 kcal/m2 min
Solution
We know that, for a source, emitting energy E at temperature T
E = σT4 ⇒ E1 = σ(2T)4

Now radiation falling on the earth will be proportional to radiation being emitted so.

Here, X is the radition falling in the earth in the lattre case.

⇒ X = 20 × 16 = 320 kcal/ m2 min
E = σT4 ⇒ E1 = σ(2T)4
Now radiation falling on the earth will be proportional to radiation being emitted so.
Here, X is the radition falling in the earth in the lattre case.
⇒ X = 20 × 16 = 320 kcal/ m2 min
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