Question

Number 12 gauge wire, commonly used in household wiring, is 2.053mm in diameter and can safely carry up to 20A. For a wire carrying the maximum current, find the magnetic field strength:

Answer 1

Answer:

The magnetic field strength is 3.9 x 10⁻³ T

Explanation:

The equation for the magnetic field strength produced by a long straight current-carrying wire is written as;

$B = \frac{\mu_o I }{2\pi r}$

Where;

μ₀ is constant = 4π x 10⁻⁷ N/A

I is the maximum current = 20 A

r is the radius of the wire = 2.053/2 = 1.0265 mm = 1.0265 x 10⁻³ m

Substitute in this values into the equation above;

$B = \frac{4 \pi X10^{-7} X 20}{2\pi X 1.0265X10^{-3} } \\\\B =3.9 X10^{-3} T$

Therefore, the magnetic field strength is 3.9 x 10⁻³ T