Question

Which of the following is an axial vector?
A. Displacement
B. Velocity
C. Torque
D. Force

Answer 1

Hint: Here first we will know what does axial vector mean and which of the options given satisfy the definition of axial vector and then we will know why other options are not considered as an axial vector.

Complete answer:
Axial vectors are those that function along the axis of rotation and represent rotational influence. Axial vectors include things like angular velocity, torque, and angular momentum.Odd numbers of cross products yield axial vectors, while even numbers yield normal vectors.

Displacement is the vector which represents linear distance between an object’s final position and initial position. As displacement does not function along the axis of rotation, it is not an axial vector.

Velocity is the vector quantity which is given as displacement per unit time. As velocity does not function along the axis of rotation, it is also not an axial vector.

Another name of torque is moment of force. Torque or moment of force is the tendency of a force to rotate or orient an object about an axis, fulcrum, or pivot. Just as force is a push or a pull, a torque can be thought of as a twist to any object. Torque is denoted by $\tau $.Torque is also a vector quantity and its SI units are Newton meter $\left( Nm \right)$. Torque is the cross product of the force and the position vector $\overrightarrow{\tau }=\overrightarrow{r}\times \overrightarrow{F}$. Therefore torque is an axial vector.

Force is a vector quantity which can change the direction of an object in motion. . As force does not function along the axis of rotation, it is also not an axial vector.

Hence, the correct answer is option (C).

Note: One should take note that an axial vector is present when the object is performing circular motion, and we can never find an axial vector when the object is in linear motion.In most cases, it is necessary that a typical physical quantity has to be provided with magnitude description and direction in a complete manner.