JEE Main202120 Jul 2021Evening ShiftPhysicsNuclear PhysicsActual
For a certain radioactive process, the graph between ln R and t ( sec ) is obtained as shown in the figure. Then the value of half life for the unknown radioactive material is approximately:
Options
- A9 . 15   sec
- B6 . 93   sec
- C2 . 62   sec
- D4 . 62   sec
Correct answer
D. 4 . 62   sec
Step-by-step solution
R = R 0 e - λ t ℓ n R = ℓ n R 0 - λ t - λ is slope of straight line λ = 3 20 t 1 / 2 = ℓ n 2 λ = 4 . 62