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NEET Sample Paper NEET Sample Test Paper-12

  • question_answer
    A black body radiates 20 W at temperature\[{{227}^{o}}C\]. If temperature of the black body is changed to\[{{727}^{o}}C\], then its radiating power will be:

    A)  120 W

    B)  240 W

    C)  320 W

    D)  360 W

    Correct Answer: C

    Solution :

     For a black body \[\frac{Q}{t}=P=A\sigma {{T}^{4}}\] \[\Rightarrow \]\[\frac{{{P}_{2}}}{{{P}_{1}}}={{\left( \frac{{{T}_{2}}}{{{T}_{1}}} \right)}^{4}}\Rightarrow \frac{{{P}_{2}}}{20}={{\left( \frac{273+727}{273+227} \right)}^{4}}\] \[\Rightarrow \]\[\frac{{{P}^{2}}}{20}={{(2)}^{4}}\Rightarrow {{P}_{2}}=320W\]  


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