An optical mirror galvanometer is used in high-precision laser projection systems. The device consists of a rectangular coil of wire suspended vertically between the curved poles of two permanent magnets, as shown in the diagram below. A lightweight mirror is attached to the top axis of rotation of the coil.
a.[3]
Explain why the coil experiences a turning force when a current flows through it.
b.[2]
In which direction will the coil turn when viewed from above? State the name of the rule you used to work this out.
Direction: …………\dots\dots\dots\dots…………
Name of rule: …………\dots\dots\dots\dots…………
c.[4]
Suggest two modifications that would increase the size of the turning force on the coil.