Question

The ratio of the energy of photon of $2000A^0$ wavelength to that of $4000A^0$ wavelength is:

• A. 1 : 4
• B. 4 : 1
• C. 1 : 2
• D. 2 : 1

Answer 1

The correct option is D 2 : 1

$E=\frac{hc}{\lambda }\Rightarrow E\propto \frac{1}{\lambda }$

$\therefore \frac{E_1}{E_2}=\frac{{\lambda }_2}{{\lambda }_1}=\frac{4000}{2000}=2:1$

Hence, option $D$ is correct.