Question

The field around a long, straight wire is:

Answer 1

Answer:

Concentric with the wire

Explanation:

The magnetic field around a long, straight current-carrying wire forms concentric lines around the wire itself. The magnitude of the field is given by:

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

where

$\mu_0$ is the magnetic permeability

I is the current in the wire

r is the distance from the wire

The direction of the lines of the field can be determined by using the right-hand rule: the thumb of the right hand points in the same direction as the current, and the other fingers (wrapped around the thumb) gives the direction of the field lines.