Question

If two electrons are separated by a distance of $0.5\mathring{A}$, then the ratio of coulomb force and weight of the electron is approximately :

• A. ${10}^{16}$
• B. ${10}^{18}$
• C. ${10}^{20}$
• D. ${10}^{22}$

Answer 1

Answer: (D)

${10}^{22}$

Coulomb force between the electrons is given by, $[F=(k\times e^2\left)/r^2\right]$
$[F=[9\times {10}^9\times (1.6\times {10}^{-19}{)}^2]/(0.5\times {10}^{-10}{)}^2]$ N.
$[F=9.2\times {10}^{-8}]$ N
weight of an electron is given by, $[W=m\times g]$
$[W=9.1\times {10}^{-31}\times 9.8]$ N
$[W=8.9\times {10}^{-30}]$ N
Now , $[F/W=9.2\times {10}^{-8}/8.9\times {10}^{-30}]$
$[F/W=1.03\times {10}^{22}]$