Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Stray voltage wikipedia , lookup
Skin effect wikipedia , lookup
Mains electricity wikipedia , lookup
Electric machine wikipedia , lookup
History of electric power transmission wikipedia , lookup
Electrification wikipedia , lookup
Alternating current wikipedia , lookup
Electricity Electricity All matter is made up of positive charges and negative charges. Electricity The positives have mass and are not usually free to move. Electricity The negatives have no mass and are free to move through some materials (conductors). Electricity Good Conductors do Not hold on to their valence electrons well – ex. metals Electricity _ + Negative charges are attracted to positive charges like mice are attracted to cheese. Static Electricity • Build up of Electrons creating Electric Charge • Created By: – Friction – Induction – Conduction Static Discharge Electricity _ + Any time there is a natural attraction between two things we can use it to make the objects do work. The negative charges (mice) will gladly do work in order to get to the positive charges (cheese). Electricity _ • Voltage: + – The amount of work that each charge (mouse) will do as it goes through the circuit. – the amount of push on the charges or – how hungry the mice are. Electricity _ • Resistance: The opposition to the flow of charge. Any appliance that asks the charge (mouse) to do work will slow it down. Resistance • Decrease • Increase – Short wire – Thick wire – Cooler wire _ __ – Long wire – Thin Wire – Warm Wire _ _ _ _ _ _ _ __ _ Electricity _ _ _ _ • Current: – The number of charges (mice) passing a point per second. The rate of flow of charges. _ _ Electricity _ _ _ _ _ _ _ _ + + + + + + + D Battery 1.5 voltes & 15 amps Electricity + _ + + + + + + _ _ _ _ AA Battery 1.5 voltes & 2.8 amps _ _ _ Electricity _ + This set up has a voltage (desire on the part of the mouse) but no current flows because there is no conductive path. It has the ability to do work but no way to get there. Circuits • Series • Parallel – One Path for e- – 2 or more Paths for e- _ _ _ _ _ _ _ _ _ _ + _ _ _ _ _ + _ Circuits • Series • Parallel _ _ _ _ _ _ _ _ _ _ + _ _ _ – 2 or more Paths for e– Add Resistors then Current Increases _ – One Path for e– Add Resistors then Current Decreases _ _ + Circuits • Series – One Path for e– Add Resistors then Current Decreases – Cells in Series Increase Voltage • Parallel – 2 or more Paths for e– Add Resistors then Current Increases – Cells in Parallel Longer Battery Life Alternating Current + + + + + + + + _ 120v _ _ _ _ _ _ _ _ _ One side of the outlet would change from cheese to cat 60 times a second. • Electrons move back and forth • Produced by Power Plants Direct Current _ _ _ _ _ _ _ _ ++ _ • Electrons move in one direction • From negative to positive • Produced by Batteries Electricity + + + + + + + _ _ _ _ _ _ _ _ The battery goes "dead" when all the negative charges make it through the circuit and get to the positive charges. Electromagnet • Moving e- produce a magnetic field – More coils / More strength Electromagnet • Moving e- produce a magnetic field – More coils / More strength – More current / More strength Generators • Electromagnetic Induction – moving an coil of wire through a magnetic field Generator Changes Mechanical Energy to Electrical Energy Motor • AC (alternating current) causes magnetic poles to flip making the armature spin Motor Changes Electrical Energy To Mechanical Energy