Question

If the energies of the two photons are in the ratio of $3:2$, their wavelengths will be in the ratio of

• A. $9:4$
• B. $2:3$
• C. $1:2$
• D. $3:2$

Answer 1

Answer: (B)

$E_1:E_2=\frac{hc}{{\lambda }_1}:\frac{hc}{{\lambda }_2}=\frac{1}{{\lambda }_1}:\frac{1}{{\lambda }_2}$

$3:2=\frac{1}{{\lambda }_1}:\frac{1}{{\lambda }_2}=\frac{{\lambda }_2:{\lambda }_1}{{\lambda }_1{\lambda }_2}$

$\therefore {\lambda }_2:{\lambda }_1=3:2$

or ${\lambda }_1:{\lambda }_2=2:3$