Question

How much current must flow through a wire to make a magnetic field as strong as Earth's field (5.00 x 10^-5 T) 1.00 m away from the wire?

Answer 1

250 A

Step-by-step explanation:

B = 5 x 10^-5 T, r = 1 m

Let current be i.

the magnetic field due to a straight current carrying conductor is given by

B = μ0 / 4π x 2i / r

5 x 10^-5 = 10^-7 x 2 x i / 1

i = 250 A