MENU

The decay constant of a radio isotope is λ. If A₁ and A₂ are its activities at time

The Decay Constant Of A Radio Isotope Is If Physics Question

The decay constant of a radio isotope is λ. If A₁ and A₂ are its activities at time t₁ and t₂ respectively, the number of nuclei which have decayed during the time (t₁ – t₂):

Options

(a) λ (A₁ – A₂)
(b) A₁t₁ -A₂t₂
(c) A₁ – A₂
(d) (A₁ – A₂) / λ

Correct Answer:

(A₁ – A₂) / λ

Explanation:

Activity is given by A = dN/ dt = -λN
Activity at time t₁ is A₁ = – λN₁
and activity at time t₂ is A₂ = -1 N₂ as t₁ > t₂ therefore, number of atoms remained after time t₁ is less than that remained after time t₂.
That is, N₁ < N₂. number of nuclei decayed in (t₁ - t₂) = N₂ - N₁ = (A₁ - A₂) / λ

Related Questions:

  1. An ideal heat engine works between temperature T₁=500 K and T₂=375 K.
  2. A nucleus disintegrates into two nuclear parts which have their velocities in the ratio
  3. Hydrogen atom in ground state is excited by a monochrmatic radiation of λ=975 Å
  4. A polarised light of intensity I₀ is passed through another polariser whose pass axis
  5. The slope of the graph showing the variation of potential difference V on X-axis

Topics: Atoms and Nuclei (136)
Subject: Physics (2479)

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

NEETLab Mobile App

Share this page with your friends

Be the first to comment

Leave a Reply

Your email address will not be published.


*