Outside a nucleus 

1. Neutron is stable

2. Proton and neutron both are stable

3. Neutron is unstable

4. Neither neutron nor proton is stable

Order of magnitude of density of uranium nucleus is (${\mathrm{m}}_{\mathrm{P}}=1.67\times {10}^{-27} \mathrm{kg}$)
(1) ${10}^{20} \mathrm{kg}/{\mathrm{m}}^3$           

(2) ${10}^{17} \mathrm{kg}/{\mathrm{m}}^3$

(3) ${10}^{14} \mathrm{kg}/{\mathrm{m}}^3$           

(4) ${10}^{11} \mathrm{kg}/{\mathrm{m}}^3$

Nucleus of an atom whose atomic mass is 24 consists of

(1) 11 electrons, 11 protons and 13 neutrons

(2) 11 electrons, 13 protons and 11 neutrons

(3) 11 protons and 13 neutrons

(4) 11 protons and 13 electrons

The mass of a neutron is very nearly the same as that of 

(1) A proton                 

(2) A meson

(3) An epsilon               

(4) An electron

The mass defect per nucleon is called

(1) Binding energy             

(2) Packing fraction

(3) Ionisation energy         

(4) Excitation energy

Nuclear forces are

(1) Short ranged attractive and charge independent

(2) Short ranged attractive and charge dependent

(3) Long ranged repulsive and charge independent

(4) Long ranged repulsive and charge dependent

Antiparticle of electron is

1. ${}_0\mathrm{n}_1$               

2. ${}_1\mathrm{H}_1$

3. Positron       

4. Neutrino

The binding energy per nucleon is maximum in the case of

(1) ${}_4{}^2\mathrm{He}$                 

(2) ${}_{26}{}^{56}\mathrm{Fe}$

(3) ${}_{56}{}^{141}\mathrm{Ba}$               

(4) ${}_{92}{}^{235}\mathrm{U}$

Isotopes are atoms having 

1. Same number of protons but different number of neutrons

2. Same number of neutrons but different number of protons

3. Same number of protons and neutrons

4. None of the above

The mass of an $\mathrm{\alpha }$-particle is: