KVPY2012PhysicsNuclear Physics
A radioactive nucleus A has a single decay mode with half life _ A . Another radioactive nucleus B has two decay modes 1 and 2. If decay mode 2 were absent, the half life of B would have been _ A / 2 . If decay mode 1 were absent, the half life of B would have been 3 _ A , then the ratio _ B / _ A is-
Options
- A3 / 7
- B7 / 2
- C7 / 3
- D1
Correct answer
A. 3 / 7
Step-by-step solution
array l _ B = _ A / 2 3 _ A _ A / 2 +3 _ A _ B _ A = 3 7 array