This was actually a test question:
Additional Information: This question is based on the Hall effect in a wire.
Question:
I want you to build a magnetic feild sensor. You have all the properties of the materials and the dimentions of the sensor.
a) derive a formula for a magnetic field (B) in terms of V(electric potential), I (Current), w (width) and lenght (l).
b) Can the sensor be used for just the magnetic feild or does it give direction as well? Explain.