Physics Circle home Student Login

Home›Chapters›Nuclear Physics PYQs›Law of Radioactive Decay›Question 41

JEE Main 2022 (28 Jun, Shift 2) · Law of Radioactive Decay

Law of Radioactive Decay question from JEE Main 2022 (28 Jun, Shift 2)

Q41JEE Main 2022 · 28 JUN · SHIFT 2Easy

Law of Radioactive Decay

Following statements related to radioactivity are given below:

(A) Radioactivity is a random and spontaneous process and is dependent on physical and chemical conditions.

(B) The number of un-decayed nuclei in the radioactive sample decays exponentially with time. (C) Slope of the graph of loge (no. of undecayed nuclei) Vs. time represents the reciprocal of mean life time (τ\tau).

(D) Product of decay constant (λ\lambda) and half-life time (T1/2) is not constant.

Choose the most appropriate answer from the options given below:

Show answer and solution

Answer: (c)

  1. (A) False: radioactivity is random and spontaneous but independent of physical and chemical conditions.
  2. (B) True: N=N0e−λtN = N_0 e^{-\lambda t}, an exponential decay.
  3. (C) True: ln⁡N=ln⁡N0−λt\ln N = \ln N_0 - \lambda t, slope magnitude λ=1τ\lambda = \frac{1}{\tau}.
  4. (D) False: λT1/2=ln⁡2\lambda T_{1/2} = \ln 2, a constant.
  5. So the answer is (c) (B) and (C) only.
Report a mistake

More questions on Law of Radioactive Decay