Question

The wavelength of soft X-rays is approximately $10^{-6} cm$. Calculate the frequency and energy.

Answer 1

$\quad \lambda=10^{-6} cm , \quad c=3 \cdot 0 \times 10^{10} cm / s , \quad c=v \lambda$

$\therefore \quad v=\frac{c}{\lambda}=\frac{3 \times 10^{10} cm s ^{-1}}{10^{-6} cm }=3 \times 10^{16} s ^{-1}$

Again, energy $(E)=h v$

$=\left(6.6 \times 10^{-27} \text { erg.s }\right) \times\left(3.0 \times 10^{16} s ^{-1}\right)= 1 \cdot 98 \times 10^{-10} erg .$