Q.

In hydrogen like system the ratio of coulombian force and gravitational force between an electron and a proton is in the order of          [2024]

1 1039  
2 1019  
3 1029  
4 1036  

Ans.

(1)     

            Fe=kQ1Q2r2=9×109×1.6×10-19×1.6×10-19r2

             Fg=Gm1m2r2=6.67×10-11×9.1×10-31×1.6×10-27r2

             FeFg0.23×10402.3×1039