JEE Main & Advanced Physics Transmission of Heat Question Bank Topic Test - Transmission of Heat (3-5-21)

  • question_answer
    A black body of surface area \[10\,c{{m}^{2}}\] is heated to \[127{}^\circ C\] and is suspended in a room at temperature \[27{}^\circ C\]. The initial rate of loss of heat from the body at the room temperature will be            

    A) 2.99 W

    B) 1.89 W

    C) 1.18 W

    D)  0.99 W

    Correct Answer: D

    Solution :

    Loss of heat \[\Delta Q=A\varepsilon \sigma ({{T}^{4}}-T_{0}^{4})t\] \[\Rightarrow \] Rate of loss of heat \[\frac{\Delta Q}{t}=A\varepsilon \sigma ({{T}^{4}}-T_{0}^{4})\] \[=10\times {{10}^{-4}}\times 1\times 5.67\times {{10}^{-8}}{{\{273+127)}^{4}}-{{(273+27)}^{4}}\}\] = 0.99 W.

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