Question

Calculate the wave number, wavelength and frequency of light with energy of $2 \times 10^{-12} erg$.

Answer 1

SOLUTION : $E=h v ; v=\frac{E}{h}=\frac{2 \times 10^{-12} crg }{6.6 \times 10^{-27} erg . s }= 3 \times 10^{14} s ^{-1}$

$\lambda=\frac{c}{v}=\frac{3 \times 10^{10} cm s ^{-1}}{3 \times 10^{14} s ^{-1}}=1 \times 10^{-4} c m$

$\bar{v}=\frac{1}{\lambda}=\frac{1}{1 \times 10^{-4} cm }=1 \times 10^{4} cm ^{-1} \text {. }$