A) 410 watt
B) 405 watt
C) 200 watt
D) 81 watt
Correct Answer: B
Solution :
Here: Initial radiated energy \[{{E}_{1}}=5\,watt\] Initial temperature \[{{T}_{1}}=400\,K\] Final temperature \[{{T}_{2}}=1200\,K\] According Stefans law that energy \[E\propto {{T}^{4}}\] Hence, \[\frac{{{E}_{1}}}{{{E}_{2}}}={{\left( \frac{{{T}_{1}}}{{{T}_{2}}} \right)}^{4}}\] or \[\frac{5}{{{E}_{2}}}={{\left( \frac{400}{1200} \right)}^{4}}\]You need to login to perform this action.
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