Q. When $\ _{92}U^{235}$ undergoes fission, 0.1% of its original mass is changed into energy. How much energy is released if $1kg$ of $\ _{92}U^{235}$ undergoes fission
A) $9 \times 10^{10}J$
B) $9 \times 10^{11}J$
C) $9 \times 10^{12}J$
D) $9 \times 10^{13}J$
Explanation
(d) $E = \mathrm{\Delta}mc^{2},\mathrm{\Delta}m = \frac{0.1}{100} = 10^{- 3}kg$
$\therefore E = 10^{- 3} \times \left( 3 \times 10^{8} \right)^{2} = 10^{- 3} \times 9 \times 10^{16} = 9 \times 10^{13}J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.