MHT CET20225 Aug 2022Evening ShiftPhysicsNuclear PhysicsActual
For a substance, fraction of its initial quantify ( N ₀ ) which will disintegrate in its average life time is about ( e =2.71)
Options
- A( 1 3 ) N ₀
- B( 1 2 ) N ₀
- C( 2 3 ) N ₀
- D(0.9) N ₀
Correct answer
C. ( 2 3 ) N ₀
Step-by-step solution
For a radioactive substance, N = N ₀ e ^ - t Given the mean life, t = 1 N = N ₀ e ^ - 1 = N ₀ e = N ₀ 2.71 =0.37 ~N ₀0.37 ~N ₀ is the amount of radioactive substance left after time . The amount disintegrated in time = N ₀-0.37 ~N ₀=0.63 ~N ₀= 2 3 ~N ₀