A radioactive nucleus decays by two different processes. The half life for the first process is 10 s and that for the second is 100 s. The effective half life of the nucleus is close to :

Activities of three radioactive substances A, B and C are represented by the curves A, B and C, in the figure. Then their half-lives
$${T_{{1 \over 2}}}\left( A \right)$$ : $${T_{{1 \over 2}}}\left( B \right)$$ : $${T_{{1 \over 2}}}\left( C \right)$$ are in the ratio :

Find the Binding energy per neucleon for $${}_{50}^{120}Sn$$. Mass of proton m_p = 1.00783 U, mass of neutron m_n = 1.00867 U and mass of tin nucleus m_Sn = 119.902199 U. (take 1U = 931 MeV)

Hydrogen ion and singly ionized helium atom are accelerated, from rest, through the same potential difference. The ratio of final speeds of hydrogen and helium ions is close to :