You are designing a new solenoid and experimenting with material for each turn. The particular turn you are working with is a circular loop of radius 4.50 cm that carries a current of 20.0 A.
Calculate the magnetic field $B$ at the center of the loop.
Use $4 \times 10^{-7}$ T\text{-}m/A for the permeability of free space $\mu_0$.
Consider the coordinate system in the figure.
$B =
$
If the circular loop lies in the xy plane and if the current flows clockwise around the loop, which direction does the magnetic field point inside the loop?
$\circ$ positive z
$\circ$ negative z
$\circ$ positive x
$\circ$ negative y
If the radius is decreased, what will happen to the magnetic field?
$\circ$ stay the same
$\circ$ none of these
$\circ$ decrease
$\circ$ increase
