The magnetic field at a distance of 2 cm from a long straight current-carrying wire is 4 μT.What is the magnetic field at a distance of 1 cm from this wire?
A)2 μT
B)4 μT
C)6 μT
D)8 μT
E)10 μT

Question

Quizplus · Accepted Answer

The magnetic field (B) around a long straight conductor is given by B = μ₀I/(2πr), where μ₀ is the permeability of free space, I is the current, and r is the distance from the wire. This formula shows that the magnetic field is inversely proportional to the distance from the wire. Therefore, if the distance is halved, the magnetic field will double. Since the magnetic field at 2 cm is 4 μT, at 1 cm, it will be 8 μT.

The Magnetic Field at a Distance of 2 Cm from a Long