I solved that the current in a long straight wire that would produce a magnetic field twice the strength of the Earth's field at a distance of 5 cm from the wire. Earth's field is about 5*10^-5 T.

B = 2 * 5 * 10^-5 = 1 * 10^-4 T

B = mu₀ I / 2 pi r

1 * 10^-4 = (4 pi * 10^-7 * I) / (2 pi * 0.05)

I = ( 1 * 10^-4 * 2 pi * 0.05 ) / ( 4 pi * 10^-7 )

I = 25 A

I want this example done with different numbers:

Q: The current in a long straight wire that would produce a magnetic field 100 times the strength of the Earth's field at a distance of 1 cm from the wire. Earth's field is about 5*10^-5 T.