The process that mainly takes place in stars to produce energy is:

Choose the correct option to complete the net effect of the fusion reaction that occurs in the Sun: $4_1^1H + 2e^- \rightarrow$ . . . . . . $+ 2\nu + 6\gamma +$ . . . . . .

The binding energy of deuteron is $2.2 \, MeV$ and that of $_2^4He$ is $28 \, MeV$. If two deuterons are fused to form one $_2^4He$,then the energy released is ......... $MeV$.

Calculate the height of the potential barrier for a head-on collision of two deuterons. (Hint: The height of the potential barrier is given by the Coulomb repulsion between the two deuterons when they just touch each other. Assume that they can be taken as hard spheres of radius $2.0 \; fm$.)

Solar energy is mainly caused due to

In the proton-proton cycle, four hydrogen nuclei combine to release energy of ....... $MeV$.