Transcript Electricity
Electricity Basic Terms #1 John Jones Ampere – rate of electrical flow (volume of electricity flowing) Sometimes referred to as amps Voltage or electromagnetic force – a measure of electrical pressure Also abbreviated EMF or E Resistance The opposition to the flow of electrons through a conductor – measured in Ohms Watt Refers to the amount of power derived from a device or the rate of doing work Example – 100 watt light bulb 1500 watt blow dryer Kilowatt = 1000 watts Kilo-watt hour Electricity is sold by the kilowatt hour (gasoline is sold by the gallon) Using 1000 (kilo) watts for one hour is a KWH Watts and Horsepower 746 watts = one horsepower Watts = Volts x Amps Sometime referred to as the West Virginia Formula. The amount of work that can be done in a circuit is equal to the voltage in the circuit times the amps WVA Analagy You can wash your car (do work) faster is you have a large hose with lots of pressure. A large hose will allow for greater flow of water (flow = amps) Pressure would be = voltage (force) Circuit A controlled path for electricity to flow beginning at the source (usually a breaker), traveling to the consumer (ex. light) and back to the source. The colored wire goes to the consumer and the white wire “comes back” to complete the circuit Unless a complete circuit is made – the devices will not work Breakers and switches are usually used to control the flow National Electrical Code Set of guidelines for use when designing and installing electrical service and devices Conductor Substance that will allow for the flow of electricity Most common: copper, aluminum Best Conductor: Gold Insulator Substance that does not allow for the flow of electricity Plastic, rubber Parallel Circuit A circuit that has more than one way that electricity can flow. Most common type of circuit Series Circuit Has only one pathway for electricity to follow. If there are more than one device in the circuit, the electricity must flow through one device and continue on to the next device. Not normally used in houses. Christmas lights are sometimes wired in series. That is why if one bulb goes out the whole line goes out W = V*A A device (such as a light) hooked to a 120 volt circuit that is pulling 5 amps would be using how many watts? W = 120*5 W = 600 W=V*A Also means that: V = W / A (watts divided by amps) A = W / V (watts divided by volts) Calculating Amps Calculate the amperage of a 600 watt light bulb that is running on a 120 volt circuit. A= 600/120 or 5 amps Calculate Voltage What is the voltage on a circuit that has a 600 watt bulb that is pulling 5 amps. V=W/A Voltage = 600/5 120 volts