Nuclear Physics

Q: The deuteron is bound by nuclear forces just as H-atom is made up of p and e bound by electrostatic forces. If we consider the force between neutron and proton in deuteron as given in the form a coulomb potential but with an effective charge e’
$F = \frac{1}{4\pi \epsilon_0}\frac{e’^2}{r}$ . Estimate the value of (e’/e) given that the binding energy of a deuteron is 2.2 MeV.

Q: A nuclide 1 is said to be the mirror isobar of nuclide 2 if Z₁ = N₂ and Z₂ = N₁.

(a) What nuclide is a mirror isobar of ₁₁Na²³ ?

(b) Which nuclide out of the two mirror isobars have greater binding energy and why ?

Q: Which sample A or B shown in figure has shorter mean –life ?

Q: The variation of decay rate of two radioactive samples A and B with time is shown in figure.Which of the following statements are true ?

(a) Decay constant of A is greater than that of B, hence A always decays faster than B

(b) Decay constant of B is greater than that of A but its decay rate is always smaller than that of A

(c) Decay constant of A is greater than that of B but it does not always decay faster than B

(d) Decay constant of B is smaller than that of A but still its decay rate becomes equal to that of A at a later instant

Ans: (c) & (d)

Q: Samples of two radioactive nuclides A and B are taken λ_A and λ_B are the disintegration constant of A and B respectively. In which of the following cases, the two samples can simultaneously have the same decay rate at any time ?

(a) Initial rate of decay of A is twice the initial rate of decay of B and λ_A = λ_B

(b) Initial rate of decay of A is twice the initial rate of decay of B and  λ_A > λ_B

(c) Initial rate of decay of B is twice the initial rate of decay of A and λ_A > λ_B

(d) Initial rate of decay of B is same as the rate of decay of A at t = 2h and λ_A < λ_B

Ans: (b) & (d)