Suppose the charge of a proton and an electron differ slightly. One of them is $– e$, the other is $(e + \Delta e)$. If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then $\Delta e$ is of the order of [Given mass of hydrogen $mh = 1.67 \times 10^{–27} kg$]

Question

( A ) $10^{-23} C$
( B ) $10^{-47} C$
( C ) $10^{-20} C$
( D ) $10^{-37} C$