Complex sentence: In a clutch, (B1) when powers applied a magnetic field is created in the coil (A2 blue) this field (flux) overcomes an air gap between the clutch rotor (A2 yellow) and the armature (A2 red).
Split into simpler sentences: In a clutch, (B1) when powers applied, a magnetic field is created in the coil (A2 blue). This field (flux) overcomes an air gap between the clutch rotor (A2 yellow) and the armature (A2 red).