JEE Main201815 Apr 2018Morning ShiftPhysicsNuclear PhysicsActual
A solution containing active cobalt ₂₇⁶⁰ Co having activity of 0.8 Ci and decay constant is injected in an animal's body. If 1 ~cm ^3 of blood is drawn from the animal's body after 10 hrs of injection, the activity found was 300 decays per minute. What is the volume of blood that is flowing in the body? (1 Ci =3.7 10¹⁰ . decay per second and at . t =10 hrs ^ - t =0.84 )
Options
- A6 litres
- B7 litres
- C4 litres
- D5 litres
Correct answer
D. 5 litres
Step-by-step solution
Let initial activity = No =0.8 ci 0.8 3.7 10^4 dps Activity in 1 ~cm ^3 of blood at t =10 hr , n = 300 60 dps =5 dps N = Activity of whole blood at time t =10 hr . Total volume of the blood in the person, V = N n = N₀ e- t n = 0.8 3.7 10^4 0.7927 5 5 litre