The magnitude of the induced electromotive force (EMF) is directly proportional to the rate of change of magnetic flux linkage.

The direction of an induced electromotive force (EMF) is such that it opposes the change in magnetic flux that produces it.

The electric current through a conductor is directly proportional to the potential difference across it, provided the temperature remains constant.

The electrostatic force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.