Final answer:
According to Gauss' Law of Electrostatics, the quantity measured on a surface equal to the charge enclosed is the electric flux. It states that electric flux through a closed surface is proportional to the enclosed charge and illustrates the relationship between electric charges and the electric field they produce.
Step-by-step explanation:
According to Gauss' Law of Electrostatics, the quantity measured on a surface that is equal to the charge enclosed by that surface is the electric flux. This law states that the electric flux through any closed surface surrounding a point charge is proportional to the amount of charge enclosed, regardless of the size or shape of the surface. If we imagine drawing a spherical surface enclosing a charge, there is a net electric flux of field lines flowing outward (or inward for a negative charge) through that surface. These field lines originate from positive charges and terminate on negative charges, indicating the direction of the electric field at each point in space.
Mathematically, Gauss's law is given by the equation Φ = qenc / εo, where Φ is the electric flux through a closed surface (Gaussian surface), qenc is the total charge enclosed within the surface, and εo is the permittivity of free space. This is a pivotal concept in understanding electric fields and is a fundamental law in electromagnetism.