JEE Main202127 Jul 2021Morning ShiftPhysicsNuclear PhysicsActual
A radioactive sample has an average life of 30 ms and is decaying. A capacitor of capacitance 200 μ F is first charged and later connected with resistor R . If the ratio of the charge on the capacitor to the activity of the radioactive sample is fixed with respect to time then the value of R should be _______Ω .
Correct answer
0
Step-by-step solution
T m = 30   ms C = 200   μ F q N = Q 0 e - t R C N 0 e - λ , t = Q 0   N 0 e λ - 1 R C Since q N is constant hence λ = 1 R C R = 1 λ C = T m C = 30 × 10 - 3 200 × 10 - 6 = 150   Ω