Navigate

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 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

admin:

Related Questions

  1. An a.c. supply gives 30 volt r.m.s which passes through a 10Ω resistance.
  2. A potentiometer circuit has been set up for finding the internal resistance of a given
  3. A wind with speed 40 m/s blows parallel to the roof of a house. The area of the roof
  4. In the Bohr’s model of hydrogen atom, the ratio of the kinetic energy to the total
  5. A radioactive element forms its own isotope after 3 consecutive disintegrations.