• # question_answer The ratio of the energy of a photon of $2000{AA}$ wavelength radiation to that of $4000{AA}$ radiation is [IIT 1986; DCE 2000; JIPMER 2000] A) 1/4        B) 4C) 1/2D) 2

$E=hv=h\frac{c}{\lambda }\,$ i.e. $E\propto \frac{1}{\lambda }$                 $\frac{{{E}_{1}}}{{{E}_{2}}}=\frac{{{\lambda }_{2}}}{{{\lambda }_{1}}}=\frac{4000}{2000}=2.$