Question

The force of attraction between two charges $8\mu C$ and $0.2N$. Find the distance of separation.

• A. $412$ meter
• B. $1.2$ meter
• C. $120$ meter
• D. $0.12$ meter

Answer 1

The correct option is B $1.2$ meter

$F=\frac{K{q}_1{q}_2}{r^2}$
$r^2=\frac{9\times {10}^9\times 8\times {10}^{-6}\times 4\times {10}^{-6}}{r^2}$
$r^2=\frac{9\times 8\times 4}{2}\times {10}^{-3}$
$r^2=\frac{9\times 8\times 4}{2}\times {10}^{-2}$
$r=12\times {10}^{-1}$ meter $=1.2m$