Consider a long, straight, thin wire carrying a steady 0.5-A current. The value of the magnetic field 5 cm from the wire is
A) $4.5 \times 10 ^ { - 6 }$ T.
B) $8.6 \times 10 ^ { - 6 }$ T.
C) $6.5 \times 10 ^ { - 6 }$ T.
D) $2.0 \times 10 ^ { - 6 }$ T.

Question

Quizplus · Accepted Answer

The magnetic field around a long straight wire is given by $ B = \frac{\mu_0 I}{2\pi r} $. Substituting $\mu_0 = 4\pi \times 10^{-7} \, \text{T}\cdot\text{m/A}$, $I = 0.5 \, \text{A}$, and $r = 0.05 \, \text{m}$, we get $ B = 2.0 \times 10^{-6} \, \text{T} $.

Consider a Long, Straight, Thin Wire Carrying a Steady 0 4.5×10−64.5 \times 10 ^ { - 6 }4.5×10−6

Consider a Long, Straight, Thin Wire Carrying a Steady 0 $4.5 \times 10 ^ { - 6 }$