Question

Find the frequency of 1 MeV photon. Given wavelength of a 1 keV photon is $1.24\times {10}^{-9}m$
Hint: $E=h\nu$

Answer 1

We know that $E=\frac{hc}{\lambda }$

$E_1{\lambda }_1=E_2{\lambda }_2$

Putting values

$1\times {10}^{3}ev\times 1.24\times {10}^{-9}=1\times {10}^{6}ev\times {\lambda }_2$

${\lambda }_2=1.24\times {10}^{-12}m$

now, $C=f\lambda$

$f=\frac{c}{\lambda }$

so $f=2.419\times {10}^{20}$