Q. If an electron and a positron annihilate, then the energy released is
A) $3.2 \times 10^{- 13}J$
B) $1.6 \times 10^{- 13}J$
C) $4.8 \times 10^{- 13}J$
D) $6.4 \times 10^{- 13}J$
Explanation
(b) Mass of electron = mass of positron $= 9.1 \times 10^{- 31}kg$
Energy released $E = (2m).c^{2}$
$= 2 \times 9.1 \times 10^{- 31} \times \left( 3 \times 10^{8} \right)^{2} = 1.6 \times 10^{- 13}J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.