Flux and Induced Voltage

Decreasing Flux Flips Polarity

The same magnitude with decreasing flux gets the opposite finite polarity. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Decreasing flux has the same magnitude case

Flux changes from 14 to 2 webers, so the magnitude of change is 12 webers.

∣ΔΦ∣=12 Wb|\Delta\Phi|=12\ \mathrm{Wb}
Induced emfChanging source-bound flux sets voltage.B=7 TA=2 m^2Phi=14 WbB=1 TA=2 m^2Phi=2 WbV=4 Vopposes decrease

The finite polarity label flips

The voltage magnitude is still 4 volts, but the polarity label now opposes the decrease.

∣V∣=4 V|V|=4\ \mathrm{V}
Induced emfChanging source-bound flux sets voltage.B=7 TA=2 m^2Phi=14 WbB=1 TA=2 m^2Phi=2 WbV=4 Vopposes decrease