What tells you how strong a electrical field is?

The energy produced as a result of this flow of electrons from atom to atom is called

Acoil suspended freely, points in some direction when no current is passed through it . can you tell what will happen when a current is passed though it?

Why does karst topography exist in some geographic location? a. few climates have enough oxygen b. most regions have rock layers other than limestone c. in most regions, the soil is too thin d. the water is too acidic enough in most places