NEET Sample Paper NEET Sample Test Paper-65

  • question_answer
    The adjoining diagram shows the spectral energy density distribution \[{{E}_{\lambda }}\] of a black body at two different temperatures. If the areas under the curves are in the ratio \[16 : 1\], the value of temperature T is

    A) 32,000 K                      

    B) 16,000 K        

    C) 8,000 K                        

    D) 4,000 K        

    Correct Answer: D

    Solution :

    \[\frac{{{A}_{T}}}{{{A}_{2000}}}\,=\,\frac{16}{1}\,\,(given)\] Area under \[{{e}_{\lambda }}-\lambda \] curve represents the emissive power of body and emissive power \[\propto \,\,{{T}^{4}}\] \[(Hence\,\,area\,\,under\,{{e}_{\lambda }}-\lambda \,curve)\propto {{T}^{4}}\] \[\Rightarrow \,\,\,\,\frac{AT}{{{A}_{2}}_{000}}\,=\,\,{{\left( \frac{T}{2000} \right)}^{4}}\] \[\Rightarrow \,\,\frac{16}{1}\,\,=\,\,{{\left( \frac{T}{2000} \right)}^{4}}\,\,\,\Rightarrow \,\,T=4000\,\,K\]


You need to login to perform this action.
You will be redirected in 3 sec spinner