NCATT AET Questions and Answers Already Passed

NCATT AET Questions and Answers Already Passed Direct current is defined as the flow of electrons in one direction throughout a circuit with constant voltage and current Faraday's Law current will flow in a circuit provided there is electrical difference in potential and there is a path for it to flow Loads slow current by applying resistance Current flows from negative to positive Atoms represent the smallest elements that exist in nature Atoms are made up of protons, neutrons and electrons Nucleaus center of the atom Electrons travel at the speed of light Protons positively charged subatomic particles Protons contain a positive electrical potential Protons positive charge affect the orbits of the electrons Neutrons are neutral subatomic particles Neutrons are not involved in the conduction of electricity Electron's charge is negative The speed of rotation combined with electrical potential keeps the electrons in their orbits The attraction of opposite charges holds the electron in its orbit Conductors easily permit the movement of electrons from an electrical source to a load and back to the electrical source with a minimum of resistance First two inner orbits make up the atomic number for the element During conductance an extra valence electron flows into the next atoms valance orbit Good conductors Only those elements that dont hang on to their valence electrons Good Insulators Elements that don't give up valance electrons no matter what force is applied lators a material or device used to prevent the passage of heat, electricity or sound from one medium to another Examples of insulators Glass, Mica, Silica Air can be a good insulator but will spark when enough electrical force is applied Static Electricity an electrical charge that may be built up on a non-conductive surface by friction Static electricity serves no useful purpose in aviation and cost millions of dollars in damage every year Voltage electric potential energy per unit charge measured in joules per coulomb Coulomb basic unit of electrical quantiy Coluomb is equal to 6.28 billion-billion electrons Coluomb is the actual count of electrons in a unit of measure Joule amount of electrons in a suspended state as compared to some electrons in an adjacent part of the circuit Electromotive Force is the force required to move an electron measured in volts EMF is the force required to cause one amp of the current of flow through one ohm of reistance Mechanical, Chemical, Friction three methods used to generate EMF Volt basic unit of measure of electrical pressure A Volt is that amount of force required to cause on amp of current to flow through one ohm of resistance E is the symbol for volts Current is the flow of electricity that pass a given point in a specific amount of time I is the symbol for amps Amps unit of measure used to express the flow of electrons