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  3. RAJASTHAN ­ PET

RAJASTHAN ­ PET Rajasthan PET Solved Paper-2001

  • question_answer
    An object is at a temperature of\[400{}^\circ C\]. At what temperature would it radiate energy twice as fast? The temperature of the surroundings may be assumed to be negligible

    A)  \[200{}^\circ C\]           

    B)  200 K

    C)  \[800{}^\circ C\]           

    D)  800 K

    Correct Answer: D

    Solution :

     In first state, \[E=\sigma {{(673)}^{4}}\] In second state, \[2E=\sigma {{T}^{4}}\] \[\therefore \] \[\frac{1}{2}={{\left( \frac{673}{T} \right)}^{4}}\] \[T={{(2)}^{1/4}}\times 673=800\,K\]


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