Question

$F_g$ and $F_e$represents gravitational and electrostatic force respectively between electrons situated at a distance 10 cm apart. The ratio of $F_g$ and $F_e$ is of the order of

• A. ${10}^{42}$
• B. ${10}^{40}$
• C. $10$
• D. ${10}^{-43}$

Answer 1

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

Gravitational force between electrons $F_g=\frac{G(m_e{)}^2}{r^2}$
Electrostatic force between electrons$F_e=\frac{k{e}^2}{r^2}$
Ratio :$\frac{F_g}{F_e}$ $=$ $\frac{G(m_e{)}^2}{k{e}^2}$ $=\frac{6.67\times {10}^{-11}\times {(9.1\times {10}^{-31})}^2}{9\times {10}^9\times {(1.6\times {10}^{-19})}^2}=2.39\times {10}^{-43}$