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Current Electricity. Currents. Current Electricity - the flow of electrons through a wire. Measured in Amperes (A) - The amount of current that flows past a given point per second.
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Currents • Current Electricity- the flow of electrons through a wire. • Measured in Amperes (A)- The amount of current that flows past a given point per second. • Once electrons are pushed into moving, they can be made to continue flowing provided they have a path and a source.
More Currents • Flowing charges are due to: • Solids: Electrons • Liquids: Ions • In order for a current to be produced, there must be a source of electrons.
Voltagein Currents • Voltage- The measure of energy available to move electrons • It is the push that makes electrons move • The higher the voltage, the more energy each electron carries, the more energy electron carries, the more work it can do.
Types of Currents • Direct Current (DC) – When electrons always flow in the same direction • Used in: Dry Cells, Batteries, Thermocouples • Alternating Current (AC) - When electrons reverse their direction regularly • Reverse direction about 60 times per second • Most commonly used current
Tesla Coil • DO NOT WRITEType of circuit invented by Nikola Tesla • High voltage • Low current • High frequency • Uses an Alternating Current • And….. Very cool musical instrument as well….Super Mario BrothersStar WarsMortal Kombat
Resistance • Resistance- Opposition to the flow of electricity • Measured in OHMs(Ω) • Resistance of a wire depends on: • Material – good/bad conductor • Thickness- thin wire = more resistance, less room for electrons to flow • Length- longer wire= more resistance-greater distance to travel • Temperature- higher= more resistance
OHM’s Law • George Ohm- Studied the relationship of voltage, current, and resistance in electric circuits. • Equation: Current (I)= Voltage (v)/ Resistance (R) I= V/R • Units • Current: Amperes • Voltage: Volts • Resistance: Ohms
Ohm’s Law Example • What is the current through a wire that has a resistance of 30 OHMs if the voltage is 45 volts?Equation: I=V/R