At point $P$ the magnetic field due to a long straight wire carrying a current of $2.0 \mathrm {~A}$ is $1.2 \mu \mathrm { T }$. How far is $P$ from the wire? $\left( \mu _ { 0 } = 4 \pi \times 10 ^ { - 7 } \mathrm {~T} \cdot \mathrm { m } / \mathrm { A } \right)$
A) $22 \mathrm {~cm}$
B) $55 \mathrm {~cm}$
C) $33 \mathrm {~cm}$
D) $11 \mathrm {~cm}$
E) $44 \mathrm {~cm}$

Question

Quizplus · Accepted Answer

The magnetic field $B$ due to a long straight wire is given by $B = \frac{\mu_0 I}{2\pi r}$. Solving for $r$, we get $r = \frac{\mu_0 I}{2\pi B}$. Substituting the given values, $r = \frac{4\pi \times 10^{-7} \times 2}{2\pi \times 1.2 \times 10^{-6}}$, which simplifies to $r = 0.33 \, \text{m} = 33 \, \text{cm}$.

At Point PPP The Magnetic Field Due to a Long Straight Wire Carrying

At Point $P$ The Magnetic Field Due to a Long Straight Wire Carrying