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17 Cards in this Set
- Front
- Back
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electron in outer shell of its atoms and aren't anchored and can wander freely ex: Metals such as copper and aluminum |
Conductor |
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electron tightly bounded and belong to particular atoms, are anchored, are not free to go to other atoms ex: rubber, glass |
Insulator |
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material that can be made to behave sometimes as an insulator and sometimes as a conductor -conducts when light is shined on it -insulators in their pure state -conductor when they have impurities |
Semiconductor |
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materials acquire zero resistance (infinite conductivity) to the flow of charge. -once electric current is established, it will flow indefinitely -no heat loss occurs when charges flow -no energy is lost with no electrical resistance |
Superconductor |
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if you bring a charged object near a conducting surface, electrons are made to move in the surface material even without physical contact |
Charging by Induction |
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When the ends of an electrical conductor are at different electric potentials--when there is a potential difference--charge flow from one to the other Analogues to water flowing from higher pressure to lower pressure |
Flow of Charge |
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Electric current where conduction of electrons are charge carriers that are free to move throughout atomic lattice. Protons are bound within the nuclei of atoms |
In metal wires |
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Electric current where positive ions and electrons constitute electric charge flow. |
In fluids |
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measured in ampere (1 coulomb of charge per second) speed of electrons (drift speed) through a wire is slow because of continuous bumping of electrons in wire charge flows through a circuit, voltage is established across a wire |
Rate of Electric Flow |
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Circuit elements that regulate current inside electrical devices |
Resistors |
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Thin wires have _______ resistance than thick wires Doubling the length, ____________ the resistance Higher the temperature, _________ the resistance. Rubber much more resistant than copper of same size |
more doubles more |
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Relationship in a circuit between voltage, current, and resistance States that the current in a circuit varies in direct proportion to the potential difference, or voltage, and inversely |
Ohm's Law current = voltage / resistance |
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flows in one direction only electrons always move from the negative terminal toward the positive terminal |
Direct current (dc) |
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electrons in the circuit are moved first in one direction and then in opposite direction, alternating to and fro about fixed positions accomplished by alternating the polarity of voltage at the generator |
Alternating Current (ac) |
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North America alternating current 60 cycles per second voltage is 120 V |
Europe Voltage is 240 V Power transmission is more efficient when higher |
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tiny electronic device that acts as a one-way valve to allow electron flow in one direction only |
Diode |
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rate at which electric energy is converted into another form power= current x voltage; in units watts ex: 100 watt lamp draws .8 ampere |
Electric Power |
