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
17.2 Electric Current and Electrical Energy ELECTRIC CURRENT is the rate at which charges pass a given point, this is expressed in amperes (amps) When you turn something on an electric field is set up along the wire which allows the free electrons in the wire to move transferring the energy to the next electron The current moves quickly however the electrons moves slowly DIRECT CURRENT the charges flow the same direction ALTERNATING CURRENT the charges shift directions VOLTAGE is the potential difference between two points in a circuit You can think of voltage as the amount of energy released RESISTANCE is the opposition to the flow of electric charge, it can be thought of as electrical friction Good conductors have low resistance Resistance tends to increase with temperature Superconductors are materials where the temperature can be dropped so low that there is hardly any resitance Cells change chemical or radiant energy into electrical energy (a battery is a cell, not biological cells) Cells are made of electrolyte which is a chemical that allows electricity to flow, an electrode is the part the electricity enters or exits Wet cells have liquid electrolyte and dry cells have dry or pastelike electrolytes THERMOCOUPLE converts thermal energy into electrical energy PHOTOCELLS convert light energy into electrical energy