Question

Two straight wires separated by a very small distance run parallel to each other, one carrying a current of 4.0 A to the right and the other carrying a current of 8.7 A to the left.Give the approximate value for the magnitude of the magnetic field a large distance r from both wires.B=........................(1/r) T.m

Answer 1

To solve this problem we must simply consider the concept given for the magnetic field from the Ampere law.

For which you have to

$B = \frac{\mu_0 I}{2\pi r}$

Where,

$\mu_0 =$Permeability constant

I = Current

r = Distance

Re-organizing the equation so that it can be expressed in terms of the magnetic field and the radius we have to

$B = \frac{\mu_0 I}{2\pi} * \frac{1}{r}$

Replacing the change of current and the permeability constant

$B = \frac{(4\pi * 10^{-7}) (8.7-4)}{2\pi} * \frac{1}{r}$

$B = (2* 10^{-7}) (8.7-4) * \frac{1}{r}$

$B = (9.4* 10^{-7})* \frac{1}{r}$

Therefore the approximate value for the magnitude of the magnetic field a large distance r from both wires is $(9.4* 10^{-7})* \frac{1}{r} T\cdot m$