Two deuterons are fused to form one alpha particle. If binding energy per nucleon of deuterium is 1.05 MeV and that of alpha particle is 7 MeV , what is the energy released in the formation of one alpha particle from the fusing of two deuterons?

An atom with one electron has ionization energy of 24 eV . An electron in this atom makes a transition from an excited energy level, where $\mathrm{E}=-15 \mathrm{eV}$, to the ground state. What is the wavelength of the emitted photon from this transition?

If the mass numbers of two nuclei are in the ratio $5: 2$ and their diameters are in ratio $2: 6$. Then their nuclear densities will be in the ratio

Which of the following is correct in the case of the Bohr model of atoms?

A. Predicts continuous emission spectra for all atoms

B. Assumes that the angular momentum of electrons is quantised

C. Predicts same emission spectrum for singly ionised neon atom and hydrogen atom

D. Predicts same emission spectrum for singly ionised neon atom and singly ionised helium atom