Question

Two parallel wires on of length $1m$ and other is infinitive, are lying at a distance of $2m$. If the current flowing in each wire is $1$ ampere then the force between them will be-

• A. $2\times {10}^{-7}N$
• B. ${10}^{-7}N$
• C. $0.5N$
• D. ${10}^{7}N$

Answer 1

The correct option is B ${10}^{-7}N$

The force between the two parallel wires one of length $1m$ and other in infinite,

$F=\frac{{\mu }_0{I}_1{I}_{2}l}{2\pi d}$. . . . . .(1)

Given,

$I_1=I_2=1A$

$d=2m$

$l=1m$

${\mu }_0=4\pi \times {10}^{-7}$

Put all value in equation (1), we get

$F=\frac{4\pi \times {10}^{-7}\times 1\times 1\times 1}{2\pi \times 2}$

$F={10}^{-7}N$

The correct option is B.