A single conducting loop has a radius equal to $3\mathrm{.}0$ cm and carries a current equal to $2\mathrm{.}6$ A$.$ What is the magnitude of the magnetic field on the line through the center of the loop and perpendicular to the plane of the loop $($a$)$ at the center of the loop, $($b$)1\mathrm{.}0$ cm from the center, $($c$)2\mathrm{.}0$ cm from the center, and $($d$)35$ cm from the center?