# Question regarding Faraday's law on induction

• B
The law states:

The induced electromotive force in any closed circuit is equal to the negative of the time rate of change of the magnetic fluxenclosed by the circuit.

So, what if the change is flux changes are proportionately equal parts of opposite polarities? Suppose you approach a coil with two magnets on either side of the coil, each set to repel each other's north or south faces; the flux increases, but in equal parts opposite polarity. What happens exactly?

tech99
Gold Member
The law states:

So, what if the change is flux changes are proportionately equal parts of opposite polarities? Suppose you approach a coil with two magnets on either side of the coil, each set to repel each other's north or south faces; the flux increases, but in equal parts opposite polarity. What happens exactly?
If the two magnets repel each others N or S poles, then they are the same polarity and the flux in the centre will be zero. If they are opposite, N and S, then the flux will increase as they are brought closer and an EMF will be observed.

So what you're saying is that it's not enough that the flux increase, but that the flux increase must share a common polarity, and if they don't, they cancel as if there was no flux increase at all?