Static Electricity and Fundamental Electric Principles

Application of Atomic Structure to Static Electricity

• All material objects are composed of atoms.
• An atom consists of a nucleus and a vast region of space outside the nucleus.
• The nucleus of the atom contains positively charged protons and neutral neutrons.

Charging by Friction

The frictional charging process results in a transfer of electrons between the two objects which are rubbed together.

Triboelectric Series: materiales ordenados según la capacidad de tendencia de atraer electrones.

Electrizar: cargar una sustancia/cuerpo que era neutra.

Charging by Induction

Is a method used to charge an object without actually touching the object to any other charged object.

The Electroscope

An electroscope is a device which is capable of detecting the presence of a charged object.

Charging by Conduction

Involves the contact of a charged object to a neutral object.

Electric Force — Coulomb's Law

Coulomb's law states that the electrical force between two charged objects is directly proportional to the product of the quantity of charge on the objects and inversely proportional to the square of the separation distance between the two objects.

Formula: F = k · Q1 · Q2 / d²

(k = 9 · 10⁹ N·m²/C²) (d → metres) (Q → coulombs)

Electricity and Current

Electricity is a word used to describe the directional flow of electrons between atoms.

The directional movement of electrons between atoms is called electrical current.

Amperage, I (Intensity)

Ammeter: instrument to measure the flow of electrons.

Amperage: the number of electrons moving past a fixed point in a conductor in one second.

Current is measured in units called amperes or amps (A).

Voltage

EMF is electromotive force. EMF causes the electrons to move in a particular direction.

EMF is measured in units called volts (V).

Resistance

Resistance can be both good and bad: good because it gives us a way to shield ourselves from the harmful energy of electricity.

Resistance is the opposition to electrical current.

• It is measured in units called ohms (Ω).
• Resistance is sometimes desirable and sometimes undesirable.

Conductors and Insulators

Conductors conduct electrical current very easily because of their free electrons.

Insulators oppose electrical current and make poor conductors.

Some common conductors are: copper, aluminium, gold and silver.

Some common insulators are: glass, air, plastic, rubber and wood.

Ohm's Law

V = I · R

Circuit Diagrams: Series and Parallel

Wires and various components connected together form a circuit.

Circuit diagrams show how components are connected in series or parallel.

Work, Power, Joule's Law

P = V · I — power = energía × unidad de tiempo

W = I · t · V — work or energy