Volts, Ohms, Amps

Please read and answer questions.

Look for Electrical Vocabulary Words:     ampere (A),    conductor,    current (I),    insulator,    ohm (  ),    resistance,    volt (V),     electromotive force (emf),    potential difference,    potential ,      positive +,    negative - 

Basic Electrical Circuit

A basic electrical circuit consists of three main parts, a source of voltage, a load and conductors.  An example of a basic circuit could be a battery as the source of electrical energy, a lamp as the electrical load, and wires as the conductors connecting the lamp to the battery. In the source of this circuit, the battery, a chemical reaction takes place that results in ionization. This ionization produces an excess of electrons (negative charge) and a depletion of of electrons (positive charge). 

The battery  has two terminals. Theses terminals are connecting points for the two conductors. One terminals is marked with a plus (+) and the other a negative sign (-).  These two markings are referred to as polarity markings. Not all electrical devices have polarity markings. However, when polarity is a critical issue, it will be marked on the device. The proper polarity must be followed to avoid damage to equipment and/or personnel.

Voltage

Ionization can be caused by forces such as heat, light, magnetism chemical action, or mechanical pressure. This results in the creation of an electrical voltage. What is voltage? Voltage is the force behind electron flow. In the simple circuit just described, the battery was the source of electrical energy.  This battery has a rating of 6 volts. The volt (v) is the electrical unit used to express  the amount of electrical pressure present, or the amount of electrical force produced by the chemical action inside the battery.

The term voltage is used to express the amount of electrical force in much the same way we use horsepower to express the amount of mechanical force for an automobile. Electrical pressure or voltage can also be expressed as potential, potential difference, or as electromotive force (emf). For our purposes, these terms mean the same thing. Voltage, is usually represented by the capital letter E or V.

Current

Electrical current is the flow of electrons. The amount of electrons flowing past any given point in one second is rated in the electrical unit ampere (A). The ampere is expressed using the letter I.  The ampere describes the rate of flow of the electrons past any given point in a circuit. One ampere is equal to one coulomb of charge flowing past a point in one second.

Resistance

All electrical circuits have resistance. Resistance is the opposition to the flow of electrons.  Resistance is measured in ohms, and the electrical symbol for ohm is (the Greek letter omega). A good conductor of electricity is any thing that permits the free flow of electrons. A poor conductor of electricity is a material that that will not permit the free flow of electrons. Extremely poor conductors are referred to as insulators.

Conductors: 

copper          iron     steel       aluminum       tin      damp earth          salt water

Insulators:

glass         mica          porcelain        air        dry wood        distilled water        paper      rubber      oil             some plastics         bakelite