The Magnetic Field at a Distance Of $2 \mathrm {~cm}$ From a Long Straight Current-Carrying Wire Is

Multiple Choice

The magnetic field at a distance of $2 \mathrm {~cm}$ from a long straight current-carrying wire is $4 \mu T$ . What is the magnetic field at a distance of $4 \mathrm {~cm}$ from this wire?

A) $6 \mu \mathrm { T }$
B) $4 \mu \mathrm { T }$
C) $10 \mu \mathrm { T }$
D) $2 \mu \mathrm { T }$
E) $8 \mu T$