Ohm's Law defines the relationship between voltage, current and resistance
It is described as
![](http://4.bp.blogspot.com/-sxPaVwg5DOA/USdIXjU_4TI/AAAAAAAAGG0/-rLUB-BxjA0/s1600/interpoles-725826.jpg)
Voltage = Current x Resistance
Similarly, Hopkinson's Law can be written as
Magnetomotive Force = Flux x Reluctance
Hopkinson's Law is also known as Rowland's Law