Three before-after flux rows show voltage magnitude from change size and polarity from change direction.
Changing flux sets voltage size, while the sign of change sets 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
Small increase gives two volts
Flux goes from 2 Wb to 8 Wb, so change size 6 Wb over 3 s gives 2 V and polarity opposes the increase.
V=∣8−2∣/3=2
Larger increase gives four volts
Flux goes from 2 Wb to 14 Wb, so change size 12 Wb over 3 s gives 4 V and polarity opposes the increase.
V=∣14−2∣/3=4
Equal-size decrease keeps magnitude and flips polarity
Flux goes from 14 Wb to 2 Wb, so change size 12 Wb over 3 s gives 4 V and polarity opposes the decrease.