Answer to Question #126248 in Electricity and Magnetism for tamara moses

Question

A magnetic field in a region of space produced by a long straight wire
carrying a current I has the form

Answer 1

magnetic field of a long straight wire with current I is equal to

B = $\mu_o I /2\pi r$

where $\mu_o$ is a constant with value equal to 4π* 10^-7 Tm/A

and Direction is given by right hand thumb rule.