Question

Which one of the following will be a scalar quantity?
A. electric current
B. electric field strength
C. acceleration
D. linear momentum

Answer 1

Hint: All the measurable physical quantities can be grouped into two categories, the scalar and vector quantities. Scalar quantities need only the magnitude for their definition while vector quantities require both the magnitude and direction. We should take care of each option and check whether that quantity is a scalar or a vector by applying the above criteria. This will help you in answering this question.

Complete answer:
All the quantities which can be measured can be categorized into two groups, the scalar and vector quantities. Scalars are the quantities that are fully explained by a magnitude a numerical value only. Vectors are the physical quantities that are completely defined by both the magnitude as well as direction.
A scalar quantity is the one that needs a single element of a number field for its description. Scalars are the physical quantities that only have the magnitude or a sign as well and other characteristics. A scalar is unvaried by any changes in the coordinate system. Examples for scalar quantity are volume, energy, mass density and time. In the options given, electric field strength, acceleration and linear momentum are vector quantities. Only the electric current will be the scalar one.
The correct answer has been obtained as option A.

Note:
A vector quantity is the one which is having the both of the characteristics magnitude and direction. Vectors are typically represented by an arrow whose direction will be equivalent to that of the physical quantity and the will be proportional to the magnitude of that quantity. A vector is having the magnitude and direction but it will not have a position. A vector is not changed by displacing it parallel to itself. Examples of the vector quantities are the force, velocity and torque.