Question
Question: One MeV positron encounters 1 MeV electron travelling in opposite direction. What is the wavelength ...
One MeV positron encounters 1 MeV electron travelling in opposite direction. What is the wavelength of photons produced? (Given rest mass energy of electron) or positron = 0.512MeV and h=6.62×10−34Js
A
8.2×10−11m
B
8.2×10−13m
C
8.2×10−12m
D
8.2×10−9m
Answer
8.2×10−13m
Explanation
Solution
: −10e++10e→2γ
Energy of each photon
=22(1+0.512)=1.512MeV=1.512×1.6×10−13J
As E=λhc
∴λ=Ehc=1.512×1.6×10−136.62×10−34×3×108=8.2×10−3m