NEET 2020 Model Question Paper 1

A star initially has 1040 deuterons. It produces energy via the processes.
1H2+1H2→1H3+p
1H2+1H3→2He4+n
The mass of the nuclei are as follows :
M(H2)=2.014 amu; M(p) = 1.007 amu
M(n) = 1.008 amu; M(He4)= 4.001 amu
If the average power radiated by the star is 1016 W, the deutron supply of the star is exhausted in a time of the order of :-