Q 12-13-031JEE MainJEE Main 2026 (5 Apr, Shift 2)Easy
Assuming the experimental mass of $^{12}_6C$ as $12u$, the mass defect of $^{12}_6C$ atom is ______ $\text{MeV/c}^2$.
(Mass of proton $= 1.00727$u, mass of neutron $= 1.00866$u, $1\text{u} = 931.5\ \text{MeV/c}^2$ and c is the speed of the light in vacuum).
Answer: (B) $89.03$
Mass of $6$ protons and $6$ neutrons: $6(1.00727 + 1.00866) = 12.09558$ u.
Mass defect $= 12.09558 - 12 = 0.09558$ u $= 0.09558 \times 931.5 \approx 89.03\ \text{MeV/c}^2$.
Solution by Sreeraj P, M.Sc Physics