Scalars and Vectors- PHYSICS AND ITS ELEMENTS

Scalars:

 The physical quantities that are completely characterized by magnitude is called scalars, e.g.    distance, speed, work, energy, power, temperature, current, large angles, all potential, all fluxes etc.

Vectors:

The physical quantities having both magnitude and direction are called vectors. e.g. Displacement, force, momentum, potential gradient, magnetic induction, electric dipole moment, small angles elementary area, all fields and field intensities, all gradients etc.

Tensor:

A quantity whose magnitude differs from direction to direction eg: pressure, stress, moment of inertia, modulus of elasticity, coefficient of viscosity etc.

1. Current has both magnitude and direction however; it is not a vector quantity because it does not follow the law of vector addition.
2. The necessary condition for a physical quantity to be a vector is that it should have direction while the sufficient condition is that it should follow the low of vector addition.
3. A vector quantity with zero magnitude is called a null vector.
4. A vector quantity with unit magnitude is called unit vector.