a number representing a quantity assumed to have a fixed value in a specified mathematical context

a measure of the rate of decrease in the intensity of electromagnetic radiation (as light) as it passes through a given substance; the fraction of incident radiant energy absorbed per unit mass or thickness of an absorber

the ratio of the drag on a body moving through air to the product of the velocity and the surface area of the body

the ratio of the weight of an object being moved along a surface and the force that maintains contact between the object and the surface

a measure of the induction between two circuits; the ratio of the electromotive force in a circuit to the corresponding change of current in a neighboring circuit; usually measured in henries

the ratio of the electromotive force produced in a circuit by self-induction to the rate of change of current producing it, expressed in henries