A wire carries 6.71 A. You form it into a single-turn circular loop and measure a magnetic field of 42.8 T at the loop center.

A wire carries 6.71 A. You form it into a single-turn circular loop and measure a magnetic field of 42.8 μT at the loop center.
(a) What’s the loop’s radius?
(b) What’s the field strength on the loop axis at 10.0 cm from the loop center?