The rate of radiation of a black body at \(0^{\circ} \mathrm{C}\) is \(E \mathrm{Js}^{-1}\). The rate of…

The rate of radiation of a black body at \(0^{\circ} \mathrm{C}\) is \(E \mathrm{Js}^{-1}\). The rate of radiation of the black body at \(273^{\circ} \mathrm{C}\) will be
  1. \(E \mathrm{Js}^{-1}\)
  2. \(4 E \mathrm{Js}^{-1}\)
  3. \(\frac{E}{2} \mathrm{Js}^{-1}\)
  4. \(16 E \mathrm{Js}^{-1}\)

Solution

Given, \(T_1=0^{\circ} \mathrm{C}=(0+273) \mathrm{K}=273 \mathrm{~K}\) \(T_2=273^{\circ} \mathrm{C}=(273+273) \mathrm{K}=546 \mathrm{~K}\) According to Stefan-Boltzmann's law, rate of radiation, \(\begin{array}{ll} & E \propto T^4 \\ \therefore & \frac{E_2}{E_1}=\left(\frac{T_2}{T_1}\right)^4=\left(\frac{546}{273}\right)^4=(2)^4=16 \\ \Rightarrow & E_2=16 E_1=16 E \mathrm{Js}^{-1} \quad\left[\because E_1=E \mathrm{Js}^{-1}\right] \end{array}\)

Asked in: AP EAMCET 2020 (21 Sep Shift 1)

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