An ampere is used to measure what?

"Amp" is a contraction for ampere. It is a unit of measurement for the flow of electrical current. 1 Ampere equals 1 Coulomb of electrons flowing past a point in 1 sec. Mathematically: 1 Amp = 1 C /sec For more discussion of a Coulomb see: http://en.wikipedia.org/wiki/Coulomb