Question

$F_g$ and $F_e$ represent gravitational and electrostatic forces respectively, between the two electrons situated at a distance of $10m$. The ratio $\frac{F_g}{F_e}$ is of the order of:

• A. ${10}^{43}$
• B. ${10}^{36}$
• C. ${10}^{-43}$
• D. ${10}^{-36}$

Answer 1

The correct option is C ${10}^{-43}$

$F_g=\frac{GMm}{r^2}{F}_e=\frac{k{q}_1{q}_2}{r^2}[k=9\times {10}^9=\frac{1}{4{\Pi E}_0}]$

Also, $q_1{=q}_2=qm=M=m$

$\therefore \frac{F_g}{F_e}=\frac{G{m}^2}{{kq}^2}=2.427\times {10}^{-43}$

$\therefore \frac{F_g}{F_e}$ is in order of ${10}^{-43}$.