Question

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

• A. $1/4$
• B. $1/2$
• C. $2$
• D. $4$

Answer 1

The correct option is C $2$

As we know,
energy of a photon is
$E=\frac{hc}{\lambda }$
so energy is proportional to $1/\lambda$
$\therefore \frac{E_1}{E_2}=\frac{{\lambda }_2}{{\lambda }_1}=4000/2000=2$