Question

Two long, parallel wires carry currents in the same direction. If I1 = 10 A, and I2 = 20 A, and they are d = 1.0 m apart, what is the magnetic field at a point P midway between them?

Answer 1

Answer:

The magnetic field at mid point between two parallel wires is 1.2 x 10⁻⁵ T

Explanation:

Given;

current in the first wire, I₁ = 10 A

current in the second wire, I₂ = 20 A

distance between the two wires, d = 1.0 m

Magnetic field at mid point between two parallel wires is calculated as;

$B = \frac{\mu_o I_1}{2\pi r} + \frac{\mu_o I_2}{2\pi r} \\\\B = \frac{\mu_o }{2\pi r}(I_1 +I_2)$

where;

r is the midpoint between the wires, = 0.5 m

μ₀ is the permeability of free space, = 4π x 10⁻⁷

$B = \frac{\mu_o }{2\pi r}(I_1 +I_2)\\\\B = \frac{4\pi*10^{-7} }{2\pi *0.5}(10 +20)\\\\B = \frac{4\pi*10^{-7} *30}{2\pi *0.5}\\\\B = 1.2 *10^{-5} \ T$

Therefore, the magnetic field at mid point between two parallel wires is 1.2 x 10⁻⁵ T