A nucleus at rest undergoes fission into two fragments with mass ratio 2:1. The ratio of their kinetic energies after fission is:
Correct answer: B. 1:2
- A. 1:1
- B. 1:2
- C. 2:1
- D. 3:1
Explanation
By conservation of momentum, m1 v1 = m2 v2 , where m1/m2 = 2/1. Thus, v2 /v1 = 2. Kinetic energy KE = (1/2)mv2 , so KE1 /KE2 = (m1v12 )/(m2 v22 ) = (m1/m2 ) × (v1/v22 ) = 2 × (1/2)2 = 2 × 1/4 = 1/2. Thus, the ratio is 1:2.
Last updated
About Nuclear Physics
Atomic nuclei contain protons and neutrons, with nuclear size, mass defect and binding energy describing their stability. The work covers alpha, beta and gamma decay, decay equations, half-life and decay rate, along with radiation safety and medical applications such as imaging, radiotherapy and tracers.
Practise Nuclear Physics
1,254 free Nuclear Physics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.