A) e = 0.18
B) e = 0.02
C) e = 0.2
D) e = 0.15
Correct Answer: A
Solution :
\[Q=EAt=e\sigma ({{T}^{4}}-T_{0}^{4})At\] where, t = time \[{{T}_{0}}=\]temperature of surrounding When, \[T>{{T}_{0}}\] \[Q=e\,\sigma {{T}^{4}}\,At\] \[300=e\times (5.67\times {{10}^{-8}}){{(1000)}^{4}}(5.00\times {{10}^{-4}})(60)\] \[e=0.18\]You need to login to perform this action.
You will be redirected in
3 sec