Question

What is the energy released in the fission of 2 kg of Uranium 235? (Given: energy per fission = 200 MeV)

(a) 1.64 × 10^14 J

(b) 1.64 × 10^15 J

(c) 2.64 × 10^14 J

(d) 1.64 × 10^20 J

I got this question in an interview for internship.

Origin of the question is Nuclear Force topic in section Nucleus of Physics – Class 12

Answer 1

Right choice is (a) 1.64 × 10^14 J

For explanation I would say: Given: energy per fission = 200 MeV; For Uranium 235:

The number of atoms in 235 g = 6.023 × 10^23

So, the number of atoms in 2 kg of Uranium 235 = \( ( \frac {2000}{235} )\) × 6.023 × 10^23

N = 5.125 × 10^24

Therefore, the energy released in fission of 2 kg of Uranium 235 is:

E = 200 MeV × N × 1.6 × 10^-19 J

E = 200 × 10^6 × 5.125 × 10^24 × 1.6 × 10^-19 J

E = 1.64 × 10^14 J