Question

In 3D-space, the number of elements
in a tensor of rank 2 are​

Answer 1

The answer is 9. A tensor of rank 2 is defined as a system that has a magnitude and two directions associated with it. It has 9 components. For now, we will use an example from classical electrodynamics to illustrate the point just made. density and the magnetization in free space differ in magnitude but not in direction.