Physical Science - Chapter 19
Electricity
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19A Static Electricity
- @@Electric Force@@: the field force between two charged objects
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- Electric Fields * @@Electric Field@@: a three-dimensional region around a charged object that will apply a force on other charged objects within that region * @@Electric Potential Energy@@: energy that is stored by a charged object in an electric field. the quantity depends on the magnitude of the charges and the object’s position in the field
- Methods of Charging * @@Charging by Friction@@: the process by which an object can gain excess charge while being rubbed by another object * @@Charging by Conduction@@: the process by which one charged object can produce a second charged object by the two objects being placed in contact with each other and the excess charge being shared * @@Charging by Induction@@: the process by which one charged object can produce a second charged object by allowing the electric force to move excess charge onto the second object while the two objects are not in contact with each other
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19B Current Electricity
- Electric Current * @@Current Electricity@@: electricity involving moving electric charges * @@Electric Current@@: the movement of electric charge through a complete loop * @@Electric Circuit@@: the loop through which current electricity can flow * @@Open Circuit@@: an incomplete electric circuit that prevents the movement of charge * @@Closed Circuit@@: a complete electric circuit that allows charge to flow * @@Direct Current@@: electric current in which electric charges move in only one direction * @@Conventional Current@@: the direction in a DC circuit that positive charges would flow; decided by agreement as the standard current direction
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- Understanding Direct Current
- The pump does work as it lifts the water to the storage tank, storing gravitational potential energy
- The valve controls the flow of water
- The water does work through the turbine to convert the energy into other forms
- The water continues to flow until it returns to the pump
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- The battery stores energy. When needed, the battery transforms energy from chemical potential energy to electrical energy
- The switch controls the flow of electricity
- The charge carriers do work through the lamp as the electrical energy is converted to light and thermal energy
- The change carriers continue moving through the circuit back to the battery
- @@alternating current@@: electric current in which the charge carriers change direction periodically
- Conductors and Insulators * @@electrical conductors@@: a material through which electric charge moves easily * @@electrical insulator@@: a material through which electric charge does not move easily
- Current, Voltage, and Resistance * @@ampere@@: the fundamental SI unit of electric current * @@ammeter@@: a meter used to measure electric current through a circuit * @@voltage@@: The “force” that moves electric charge carriers through an electric current; also called electric potential difference * @@voltmeter@@: a meter used to measure voltage * @@battery@@: a power source for DC electrical systems consisting of two or more electrochemical cells * @@ohm@@: the derived SI unit for electrical resistance * @@superconductor@@: a material with zero resistance
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- @@ohm’s law@@: the law that states that the current in a circuit is directly related to the voltage and inversely related to the resistance
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19C Circuits
- @@electrical load@@: an electrical device in a circuit that consumes electrical energy
- @@short circuit@@: an unintended path for an electric current
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- Series and Parallel Circuits * @@series circuit@@: a circuit with only one path that electric current can take * @@parallel circuit@@: a circuit with multiple paths that electric current can take
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- @@electrical power@@: the work per second done or produced by an electrical system
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- Electrical Safety * @@fuse@@: an electrical safety device that opens the circuit by melting when an overheated condition occurs due to excessive current * @@circuit breaker@@: an electrical safety device consisting of an automatic switch that opens when there is too much current in a circuit * @@grounding@@: the act of providing a path for electrical charge to move into the earth * @@ground-fault interrupter@@: a safety device consisting of an outlet with a built-in circuit breaker
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