Question

Two long straight parallel wires separated by 20 cm, carry 5 A and 10 A current respectively, in the same direction. Find the magnitude and direction of the net magnetic field at a point midway between them.

Answer 1

Given, I₁ = 5 A

I₂ = 10 A

We know, `B = mu_0/(4pi) (2I)/d`

So, `B_1 = mu_0/(4pi) 10/(0.1) otimes`

`B_2 = mu_0/(4pi) 20/(0.1) odot`

Thus, B = B₂ − B₁

`B = mu_0/(4 pi(0.1)) (20 - 10)`

`B = (10^-7 xx 10)/0.1`

B = 10⁻⁵ T                           ...(outward direction)