| ⇦ | 
| ⇨ |
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: - Moment of inertia of a uniform circular disc about a diameter is I. Its moment
- Six molecules have speeds 2 units, 5 units, 3 units, 6 units, 3 units and 5 units
- Which of the two have same dimensions?
- In Young’s double slit experiment, the intensity of light coming from the first slit
- If Q, E and W denote respectively the heat added, change in internal energy
Topics: Atoms and Nuclei
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- Moment of inertia of a uniform circular disc about a diameter is I. Its moment
- Six molecules have speeds 2 units, 5 units, 3 units, 6 units, 3 units and 5 units
- Which of the two have same dimensions?
- In Young’s double slit experiment, the intensity of light coming from the first slit
- If Q, E and W denote respectively the heat added, change in internal energy
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.
Share this page with your friends
Leave a Reply