Jumper cables used to start a stalled vehicle often carry a 65 a current. how strong is the magnetic field 12 cm from one cable? t compare to the earth's magnetic field (5.5 ✕ 10-5 t).

The magnetic field generated by a wire that carries a current of intensity I is :

where
is the magnetic permittivity
I is the current
r is the radial distance from the wire at which the field is calculated.

In our problem, I=65 A and r=12 cm=0.12 m, so the magnetic field is:


And we can see that the intensity of this magnetic field at r=12 cm is approximately twice the intensity of the Earth's magnetic field ()

No because scientist are still changing there mines today so they are not correct to this day