A high-voltage power line 23.0 m above the ground carries a current of 2 200 A.What is the magnetic field due to the current directly underneath the power line? (µ₀ = 4π × 10−⁷ T⋅m/A)

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Quizplus · Accepted Answer

The magnetic field due to a long, straight conductor can be calculated using the formula $B = \frac{\mu_0 I}{2 \pi r}$, where $B$ is the magnetic field, $\mu_0$ is the permeability of free space ($4\pi \times 10^{-7} \, \text{T}\cdot\text{m/A}$), $I$ is the current, and $r$ is the distance from the conductor. Plugging in the given values: $B = \frac{4\pi \times 10^{-7} \times 2200}{2\pi \times 23}$, we find $B = 19.1 \, \mu\text{T}$.

A High-Voltage Power Line 23