A gamma ray photon creates an electron- positron pair. If the rest mas – McqOptions

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1.	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 [MP PMT 1991]
A.	0.78 MeV
B.	1.78 MeV
C.	1.28 MeV
D.	0.28 MeV
Answer» C. 1.28 MeV

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