# Magnetic field generated by current in semicircular loop at a point on axis

 P: 5 1. The problem statement, all variables and given/known data Determine the magnetic field strength and direction at a point 'z' on the axis of the centre of a semi-circular current loop of radius R. 2. Relevant equations Biot Savart Formula $$d\vec{B}=\frac{\mu_{0}Id\vec{r}\times\hat{e}}{4\pi|\vec{R}-\vec{r}|^{2}}$$ e being the unit vector from r to R 3. The attempt at a solution A much simpler problem is a full current loop, because one component of the magnetic field cancels out. For this problem, you'd have to deal with the half-circle arc and the straight line base separately. I was also wondering whether its easier to calculate the z and x components of B separately as well... One component is straightforward enough... I just really don't understand where to start.
 HW Helper P: 5,004 This should be a pretty straightforward application of the Biot-Savart Law. Start by finding expressions for $\textbf{r}$, the position vector for a general point on the semi-circular arc, and $\textbf{R}$ the position vector for a general point on the $z$-axis....what do you get for those?...What does that make $\hat{\mathbf{e}}$? What is $d\textbf{r}$ for a semi-circualr arc? To makethings easier, you will want to use cylindrical coordinates.