| ⇦ | 
| ⇨ |
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: - In a compound microscope, the focal length of the objective is 2.5 cm and of eye lens
- A moving coil galvanometer of resistance 100 Ω is converted to ammeter by a resistance
- A spherical liquid drop of radius R is divided into 8 equal droplets. If the surface
- A p-n-p transistor is used in common emitter mode in an amplifier circuit.
- Two spherical nuclei have mass numbers 216 and 64 with their radii R₁ and R₂,
Topics: Atoms and Nuclei
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- In a compound microscope, the focal length of the objective is 2.5 cm and of eye lens
- A moving coil galvanometer of resistance 100 Ω is converted to ammeter by a resistance
- A spherical liquid drop of radius R is divided into 8 equal droplets. If the surface
- A p-n-p transistor is used in common emitter mode in an amplifier circuit.
- Two spherical nuclei have mass numbers 216 and 64 with their radii R₁ and R₂,
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