Find the magnetic field 6.70 cm from a long, straight wire that carries a current of 7.80 A.
answer= B_____T

I do not know what else to do for this problem. I found this formula but it is not giving me the right answer.
B= Uo*I/4pi r^2

Is my math wrong or am I going about this the wrong way?

The formula you want is:


B = \frac {\mu_0 I}{2 \pi r}


where

\mu _0 = 4 \pi \ \times \ 10^{-7} \frac {Tms} C

I knew I was off by something... thanks for your help!