Energy generation in stars is mainly due to

(1) Chemical reactions               

(2) Fission of heavy nuclei

(3) Fusion of light nuclei             

(4) Fusion of heavy nuclei

When a ${}_4{}^9\mathrm{Be}$ atom is bombarded with $\mathrm{\alpha }$ particles, one of the product of nuclear transmutation is ${}_6{}^{12}\mathrm{C}$. The other is 

(1) ${}_{-1}{}^0\mathrm{e}$           

(2) ${}_1{}^1\mathrm{H}$

(3) ${}_1{}^2\mathrm{D}$            

(4) ${}_0{}^1\mathrm{n}$

During the nuclear fusion reaction 

(1) A heavy nucleus breaks into two fragments by itself

(2) A light nucleus bombarded by thermal neutrons breaks up

(3) A heavy nucleus bombarded by thermal neutrons breaks up

(4) Two light nuclei combine to give a heavier nucleus and  possibly other products

Fusion reaction takes place at high temperature because

(1) Atoms are ionised at high temperature

(2) Molecules break-up at high temperature

(3) Nuclei break-up at high temperature

(4) Kinetic energy is high enough to overcome repulsion between nuclei

In nuclear fission, the fission reactions proceeds with a projectile. Which of the following suits the best

(1) Slow proton             

(2) Fast neutron

(3) Slow neutron         

(4) None of these

${}_1{}^1\mathrm{H}+{}_1{}^1\mathrm{H}+{}_1{}^2\mathrm{H}\to \mathrm{X}+{}_1{}^0\mathrm{e}$ energy. The emitted particle is

(1) Neutron                 

(2) Proton

(3) $\mathrm{\alpha }$ particle               

(4) Neutrino

Which of these is a fusion reaction 

(1) ${}_1{}^3\mathrm{H}+{}_1{}^2\mathrm{H}\to {}_2{}^4\mathrm{He}+{}_0{}^1\mathrm{n}$

(2) ${}_{92}{}^{238}\mathrm{U}\to {}_{82}{}^{206}\mathrm{Pb}+8\left({}_2{}^4\mathrm{He}\right)+6\left({}_{-1}{}^0\mathrm{\beta }\right)$

(3) ${}_7{}^{12}\mathrm{C}\to {}_6{}^{12}\mathrm{C}+{\mathrm{\beta }}^{+}+\mathrm{\gamma }$

(4) None of these

Hydrogen bomb is based on which of the following phenomenon

(1) Nuclear fission             

(2) Nuclear fusion

(3) Radioactive decay       

(4) None of these

Neutrino is a particle, which is 

(1) Charged and has spin

(2) Charged and has no spin

(3) Charge less and has spin

(4) Charge less and has no spin

The average number of prompt neutrons produced per fission of ${\mathrm{U}}^{235}$ is 

(1) More than 5         

(2) 3 to 5

(3) 2 to 3                 

(4) 1 to 2