Final answer:
Linear charge density is a scalar quantity that measures charge per unit length without a directional component; it's used to determine the electric field around charged objects using Gauss's law.
Step-by-step explanation:
The linear charge density of a cylinder is a measurement of charge per unit length. This quantity, represented by the symbol λ (lambda), is a scalar quantity because it only has magnitude and no direction. Charge density is a fundamental concept in electromagnetism which helps in evaluating the distribution of electric charge in different configurations. A common use of this concept is in applying Gauss's law to calculate electric fields around charged objects.
For instance, a long cylinder with a uniform charge per unit length on its surface can have its electric field inside and outside the cylinder determined by using Gauss's law. The magnitude of the electric field vector in such a situation is proportional to the net electric charge, as stated in Essential Knowledge 2.C.2 of physics curricula.
As for force, it is a vector quantity because it involves both magnitude and direction, which is true for any electric field as well.