Q. The masses of neutron and proton are $1.0087\ a.m.u.$ and $1.0073\ a.m.u.$ respectively. If the neutrons and protons combine to form a helium nucleus (alpha particles) of mass $4.0015\ a.m.u.$ the binding energy of the helium nucleus will be $(1\ a.m.u. = 931\ MeV)$
A) $28.4\ MeV$
B) $20.8\ MeV$
C) $27.3\ MeV$
D) $14.2\ MeV$
Explanation
(a) B.E. $= \mathrm{\Delta}mc^{2} = \mathrm{\Delta} \times 931\ MeV$
$= \left\lbrack 2(1.0087 + 1.0073) - 4.0015 \right\rbrack \times 931 = 28.4\ MeV$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.