Question

Force between two unit pole strength placed at a distance of one metre is

• A. $1N$
• B. $\frac{10^{-7}}{4\pi }N$
• C. $10^{-7}N$
• D. $4\pi \times 10^{-7}N$

Answer 1

Answer: (C)

$F=10^{-7}\times \frac{m^2}{r^2}$
$=\frac{10^{-7}(1{)}^2}{(1{)}^2}=10^{-7}N$