The rest mass of an electron as well as that of positron is $0.51\, MeV$. When an electron and positron are annihilate, they produce gamma-rays of wavelength(s)
- A$0.012\, \mathring A$
- B$0.024 \,\mathring A$
- C$0.012 \,\mathring A\, to \, \infty$
- D$0.024\, \mathring A \,to \,\infty$
Similar Questions
The count rate for $10\ g$ of radioactive material was measured at different times and this has been shown in the graph with scale given. The half life of the material and the total count in the first half value period respectively are
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