Question

The magnetic field a distance 2 cm from a long straight current-carrying wire is 2.0ᴇ−5 T. The current in the wire is:

A) 0.16A
B) 1.0A
C) 2.0A
D) 4.0A
E) 25A

Answer 1

The magnetic field generated by a long straight current-carrying wire decreases with distance. At a distance of 2 cm from the wire, the magnetic field is 2.0 x
`10^(-5)` T. At a distance of 20 cm, the magnetic field would be 2.0
`10^(-4)` T. At a distance of 20 cm below the wire, the magnetic field would have same magnitude but in the opposite direction.

Step-by-step explanation:

The magnetic field generated by a long straight current-carrying wire is inversely proportional to the distance from the wire. This relationship is described by Ampere's law. Therefore, if the magnetic field at a distance of 2 cm from the wire is 2.0 x
`10^(-5)`T, the magnetic field at a distance of 20 cm from the wire would be 2.0 x
`10^(-5)`T / (20 cm / 2 cm) = 2.0 x
`10^(-4)`T. Additionally, the magnetic field at a distance of 20 cm below the wire would have the same magnitude, but in the opposite direction.