KVPY2012PhysicsNuclear Physics
A parent nucleus X is decaying into daughter nucleus Y which in turn decays to Z . The half lives of X and Y are 40000 years and 20 years respectively. In a certain sample, it is found that the number of Y nuclei hardly changes with time. If the number of X nuclei in the sample is 4 10²⁰ , the number of Y nuclei present in its is-
Options
- A2 10¹⁷
- B2 10²⁰
- C4 10²³
- D4 10²⁰
Correct answer
A. 2 10¹⁷
Step-by-step solution
In radioactive equilibrium rate of decay of X = rate of decay of Y _ x N _ x = _ y N _ y , N _ x T _ x = N _ y T _ y