Question

What do you mean by magnitude of a physical quantity?

Answer 1

Hint: Go through the basics of the physical quantity. Recall how a physical quantity is represented in terms of the magnitude and unit of a particular physical quantity. Recall the method of determining the magnitude of the scalar as well as vector physical quantities.

Complete step by step solution:
All the objects in the universe have at least one physical quantity related with it. This physical quantity is the measurable property of that object.
Thus, the physical quantity can be defined as the measurable property related with an object.
A physical quantity is represented as the combination of a numerical value and a unit.
This numerical value used in the representation of the physical quantity is known as the magnitude of that physical quantity.
For example: The length of a rope is \[3\,{\text{m}}\].
In this example the physical quantity used is the length of the rope and the magnitude of this physical quantity is 3 which is written with the unit of length (m).

Additional information:
There are two types of physical quantities which are scalar quantity and vector quantity.
Both types of these scalar and vector quantities have magnitudes.
In case of the scalar physical quantity, the magnitude of the physical quantity is the positive value given along with the unit of that physical quantity.
For example, the work done in lifting a book is \[ - 6\,{\text{J}}\]. The magnitude of this scale physical quantity work is 6.
In case of the vector physical quantity, the magnitude of the physical quantity is the resultant of all the magnitudes of that quantity in all the directions present.
For example, the displacement of an object is \[ - 4\hat i + 3\hat j\]. The magnitude of this displacement is \[\sqrt {{{\left( { - 4} \right)}^2} + {3^2}} = 5\].

Note:
The magnitude of a physical quantity can also be defined in some other way. One can also define the magnitude of the physical quantity as the mod of the value given with the unit in the representation of the physical quantity. For example, the magnitude of the physical quantity length of the rope \[ - 14\,{\text{m}}\] is \[\left| { - 14} \right| = 14\].