Homework Statement
What is the induction in the centre of a spherical coil with N turns, the current I and the radius R?
Homework Equations
Biot-Savart law \mathbf{B} = \int\frac{\mu_0}{4\pi} \frac{I d\mathbf{l} \times \mathbf{\hat r}}{|r|^2}
The Attempt at a Solution
I know what...