What is the Meaning of Magnitude in Physics

Q. What is the meaning of magnitude in physics?

Answer: A magnitude is a unit of measurement that is used to specify the size or intensity of an event. It has been defined as the “amount by which something out of its usual quantity exceeds another”. A magnitude and its relative value are often represented on the same scale, for example, “a magnitude five earthquake” or “a 10-foot wall”. Magnitude may also be used to specify the size of an object in comparison to other objects. For instance, a magnitude 1 star is one-fifth as bright as a magnitude 2 star (or, put another way, 100 times less bright than a magnitude 2 star). 

The unit of measurement for mathematical variables is called a “scalar” or simply the “scalar” of that variable. In this case, the scalar value is, by definition, the magnitude of that variable. The magnitude of a quantity is sometimes called “absolute magnitude” to distinguish it from “relative magnitude”, which specifies the ratio of that quantity to a standard. The former (absolute) magnitude has units of length, area, or time and does not depend upon the unit in which it’s measured, whereas relative magnitude depends on its unit.

In physics, both scalar and vector quantities may have magnitude or intensity; for example, electric current or the surface temperature of an object has both magnitude and intensity. The magnitude of a vector is the dot product of the vector’s direction with the chosen basis vectors.