Question

The energy released when a positron is annihilated is :

• A. 0.52MeV
• B. 5.3MeV
• C. 185MeV
• D. 200MeV

Answer 1

Answer: (A)

0.52MeV

Mass of electron $=$ mass of positron
$E=\left(\Delta m\right)c^2$

$=(\frac{9.1\times {10}^{-31}}{1.6\times {10}^{-27}}\times 931.478\frac{MeV}{c^2})c^2$

$=0.52MeV$