Electric Circuits Chapter 1, Section 3

Voltage and Resistance Current in a circuit increases as the voltage increases Current in a circuit decreases as the resistance increases

Ohm’s Law The relationship between voltage, current, and resistance Current = voltage/resistance I = V/R (A) = (V)/(Ω)

Circuits Series Circuit - has only 1 path for electric current to follow If the path is broken at any point, the current will not flow and the circuit will stop working The same current flows through all devices connected to a series circuit but the resistance increases with each device

Circuits Parallel Circuit – a circuit that has more than one path for the electric current to flow through current flows through every path, so if one pathway is broken, it may not affect the others The current in each path can be different depending on the devices connected to the circuit on that path

Protecting Electric Circuits Circuits are “broken” when the current becomes larger than 15A or 20A Fuses and Circuit Breakers

Power = Current x Voltage Electric Power Electric power – the rate at which electric energy is turned into another form of energy Measured in watts (W) Power = Current x Voltage P = I x V (W) = (A) x (V)

Electrical Safety Table 2 on pg 25 – KNOW IT!! Current as low as .5A (the current needed to power a 60W light bulb) can be deadly to the body

Lightning Safety Take shelter if you can see lightning or hear thunder Avoid high places, open fields, metal surfaces, water, and isolated high objects Lightning safety position Squat low on the balls of your feet with your hands on your knees