Nuclear And Particle Physics - Study Mode

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[#16] The mass difference between the pair of mirror nuclei $${}_6^{11}C$$ xa0and xa0$${}_5^{11}B$$ is given to be Δ MeV/c 2 . According to the semi-empirical mass formula, the mass difference between the pair of mirror nuclei $${}_9^{17}F$$ xa0and $${}_8^{17}O$$ xa0will approximately be (rest mass of proton m p = 938.27 MeV/c 2 and rest mass of neutron m n = 939.57 MeV/c 2 )

(A) 1.39Δ MeV/c 2

(B) (1.39Δ + 0.5) MeV/c 2

(C) 1.86Δ MeV/c 2

(D) (1.6Δ + 0.78) MeV/c 2

Correct Answer

(A) 1.39Δ MeV/c 2

[#17] Consider a nucleus with N neutrons and Z protons. If m p , m n and BE represents the mass of the proton, the mass of the neutron and the binding energy of the nucleus respectively and c is the velocity of light in free space, the mass of the nucleus is given by

(A) Nm n + Zm p

(B) Nm p + Zm n

(C) Nm n + Zm p + $$frac{{BE}}{{{c^2}}}$$

(D) Nm p + Zm n + $$frac{{BE}}{{{c^2}}}$$

Correct Answer

(C) Nm n + Zm p + $$frac{{BE}}{{{c^2}}}$$

[#18] In the quark model which one of the following represents a proton?

(A) udd

(B) uud

(C) $${ ext{u}}overline { ext{b}} $$

(D) $${ ext{c}}overline { ext{c}} $$

Correct Answer

(B) uud

[#19] A nucleus having mass number 240 decays by α-emission to the ground state of its daughter nucleus. The Q value of the process is 5.26 MeV. The energy (in MeV) of the α particle is

(A) 5.26

(B) 5.17

(C) 5.13

(D) 5.09

Correct Answer

(B) 5.17

[#20] A relativistic particle travels a length of 3 × 10 -3 m in air before decaying. The decay process of the particle is dominated by

(A) strong interactions

(B) electromagnetic interactions

(C) weak interactions

(D) gravitational interactions

Correct Answer

(C) weak interactions