Question

The wavelength of a 1 KeV photon is $1.24\times {10}^{-9}m$. What is the frequency of 1 MeV photon?

• A. 1.24×10+15^Hz
• B. 2.4×10²⁰Hz
• C. 1.24×10¹⁵Hz
• D. 2.4×10²³Hz

Answer 1

The correct option is B

2.4×10²⁰Hz

$E=\frac{hc}{\lambda }{\lambda }^{\prime }=\frac{E}{E^{\prime }}\lambda =\frac{1Kev}{{10}^{3}kev}\times 1.24\times {10}^{-9}{\lambda }^{\prime }=1.24\times {10}^{-12}m$
So, frequency will be $2.4\times {10}^{20}Hz$.