Question

Wavelength of a 1 keV photon is $1.24 \times 10^{- 9}m$. What is the frequency of 1 MeV photon.

• A. $1.24 \times 10^{15}Hz$
• B. $2.4 \times 10^{20}Hz$
• C. $1.24 \times 10^{18}Hz$
• D. $2.4 \times 10^{23}Hz$

Answer 1

Answer: (B)

$2.4 \times 10^{20}Hz$

Answer 2

$E = h\nu \Rightarrow \nu = \frac{E}{h} = \frac{1 \times 10^{6} \times 1.6 \times 10^{- 19}}{6.6 \times 10^{- 34}} = 2.4 \times 10^{20}Hz$