Question
Question: A gamma ray photon creates an electron- positron pair. If the rest mass energy of an electron is 0.5...
A gamma ray photon creates an electron- positron pair. If the rest mass energy of an electron is 0.5 MeV and the total K.E. of the electron- positron pair is 0.78 MeV, then the energy of the gamma ray photon must be.
A
0.78 MeV
B
1.78 MeV
C
1.28 MeV
D
0.28 MeV
Answer
1.78 MeV
Explanation
Solution
Energy of γ-ray photon =0.5+0.5+0.78=1.786muMeV.