RESISTANCE
As the name implies, a resistor is an electronic component that resists the flow of electric current in a circuit. In metals such as silver or copper, which have high electrical conductivity and therefore low resistivity, electrons are able to skip freely from one atom to the next, with little resistance.
The electrical resistance of a circuit component is defined as the ratio of the applied voltage to the electric current that flows through it. The standard unit for resistance is the ohm, which is named after German physicist Georg Simon Ohm. This is defined as the resistance in a circuit with a current of one ampere at one volt. Resistance can be calculated using Ohm’s law, which states that resistance equals voltage divided by current.
Resistors are generally classified as either fixed or variable. Fixed-value resistors are simple passive components that always have the same resistance within their prescribed current and voltage limits. They are available in a wide range of resistance values, from less than one ohm to several million ohms. Variable resistors are simple electromechanical devices, such as volume controls and dimmer switches, which change the effective length or effective temperature of a resistor when you turn a knob or move a slide control.
“Electrons are able to skip freely”