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- Voltage - electrical potential
- Caused by electrons build-up compared to two different location
- Analogue to water, High pressure to low pressure until pressure same
- Units - Volt (V)
- Common source of electrons, Batteries or electric generators,
- Example, 12V car battery, Provides an electrical pressure of 12volts to a circuit connected across its terminal. Then 12J of energy are supplied to each coulomb of charge that is made to flow in circuit.
- Electrical Current - flow of electrons
- rate of electrical flow, units of amperes (I)
- 1A = rate of flow equal to 1 C (coulomb) of charge per second ( 1A = 1C/s) 1C = electric charge of 6.25 billion billion electrons)
- Electrical resistance - depended on material, increase temp increase resistance
- Ohm's Law - current(I) = voltage(V) /resistance(R)
- I = V/R
- Current is directly proportional to voltage
- Current is inversely proportional to resistance
- Ohm and Electrical Shock
- 100ohm body wet with salt water, 500,000ohms skin is very dry
- dry finger touch ends of battery, 100,000ohms
- Normal body moisture for 120V source, current is not great enough to really hurt you.
- Need Electrical Potential difference so that is why birds can sit on high voltage wires and not get electruted