The strength of an electromagnet is primarily proportional to its _____.

A) length
B) ampere-turns
C) diameter
D) core resistance

Ampere-Turns

A basic unit for measurement of magnetism. The product of number of turns of wire times current flow.

Electromagnet

A type of magnet in which the magnetic field is produced by an electric current, typically wrapping a wire around a ferromagnetic core, which can be turned on and off with the current.

Proportional

A relationship between two quantities where a change in one results in a corresponding change in the other, often depicted mathematically by a constant ratio.