A wire carries a current of 4.2 A at what distance from the wire does the magnetic field have a magnitude of 1.3×10^ -5 t

the distance is 6.46 cm.

Explanation:

Given

current in the wire, I = 4.2 A

magnitude of the magnetic field, B = 1.3 x 10⁻⁵ T

The distance from the wire is determined by using Biot-Savart Law;

Where;

r is the distance from the wire where the magnetic field is experienced

Therefore, the distance is 6.46 cm.

im not to sure what it is

c)as speed changes, wavelength and frequency change.

everything changes!