Question

When ${}_{92}^{235}U$ undergoes fission , 0.1 % of its original mass is changed into energy. How much energy is released if 1 kg of ${}_{92}^{235}U$ undergoes fission ?

• A. $9\times {10}^{10}J$
• B. $9\times {10}^{11}J$
• C. $9\times {10}^{12}J$
• D. $9\times {10}^{13}J$

Answer 1

The correct option is D $9\times {10}^{13}J$

Mass of Uranium changed into energy $=0.1$% of $1kg$$=0.001kg$

Thus energy corresponding to this energy according to Einstein's relation is, $E=m{c}^2$$=0.001\times (3\times {10}^8{)}^{2}J$$=9\times {10}^{13}J$