Question

Two parallel conductors carrying 5A each, repel with a force of 0.25 N $m^{-1}$ . The distance between them is

• A. $4\times {10}^{-5}m$
• B. $3\times {10}^{-5}m$
• C. $2\times {10}^{-5}m$
• D. $1\times {10}^{-5}m$

Answer 1

The correct option is C $2\times {10}^{-5}m$

$\frac{df}{dl}=\frac{{\mu }_0{i}_1{i}_2}{2\pi r}$

$0\cdot 25=\frac{2\times {10}^{-7}\times 5\times 5}{r}$

$r=2\times {10}^{-5}m$