Final answer:
The FA/FI ratio refers to the ratio between the flux (FA) and the induced emf (FI) in a physics context. The factors that determine the FA/FI ratio include the rate of change of current (AI/At) and the geometry of the devices.
Step-by-step explanation:
The FA/FI ratio refers to the ratio between the flux (FA) and the induced emf (FI) in a physics context. The factors that determine the FA/FI ratio include the rate of change of current (AI/At) and the geometry of the devices. The formula for FI is expressed as FI = -M*dI/dt, where M represents the mutual inductance and dI/dt represents the rate of change of current.
The faster the FA becomes closer to FI, the faster induction will occur. This is because a change in the current in one device induces an emf in the other device, and a faster rate of change of current leads to a faster induction process.