Physics - Modern Physics Question with Solution | TestHub

Energy $=\frac{12375}{5000}=2.475\mathrm{eV}=4\times 10^{-19}\mathrm{J}$ Minimum intensity to which the eye can respond. $\begin{array}{l}{1}_{\text{eye }}=(\text{ photon flux })\times \text{ energy of a photon }\\ 1_{\text{eye }}^{\text{fort }}=\left(5\times 10^4\right)\times 4\times 10^{-19}\\ =2\times 10^{-14}\mathrm{W}/{\mathrm{m}}^2\end{array}$ Now, lesser the intensity required by a detector for detection more sensitive it will $\mathrm{be}=\frac{{\mathrm{l}}_{\mathrm{ear}}}{{\mathrm{l}}_{\text{eye }}}=\frac{10^{-13}}{2\times 10^{-14}}=5$