300 likes | 412 Views
It’s Electrifying!. E-Mag. Electric Circuit. A closed path through which electrons can flow. Ex: when you turn a light switch ON, you create a CLOSED circuit, when you turn it off you are opening the circuit.
E N D
It’s Electrifying! E-Mag
Electric Circuit • A closed path through which electrons can flow. • Ex: when you turn a light switch ON, you create a CLOSED circuit, when you turn it off you are opening the circuit Phet circuit http://phet.colorado.edu/simulations/sims.php?sim=circuit_construction_kit_dc_only
Types of Circuits • Series: current has only one path to take • Parallel: current can follow different paths throughout the circuit.
Series Circuit • total resistance of the circuit is equal to the sum of individual resistance of each device in the circuit • Req = R1+ R2+ R3 …
Series Circuit • is the same in all parts of the circuit • Ieq = I1 = I2 = I3 = …
Series Circuit • Voltage drop (potential difference) can be different for each device in the circuit • Sum of voltage drops in the circuit is equal to total voltage supplied by the power source • Veq = V1 + V2 + V3 + …
SERIES CIRCUIT I stays the same V adds up R adds up
Parallel Circuit • Voltage (potential difference) is the same across each device in the circuit • Voltagedrops across each resistor in each branch equals the total voltage provided by the battery (voltage same everywhere in the circuit • VT = V1 =V2 =V3 = …
Total current in a parallel circuit equals the sum of the current in all of the branches of the circuit • Itotal = I1 + I2 + I3 More branches = More resistance
Resistors in Parallel • 1/Req = 1/R1 + 1/R2 + 1/R3…
The basics of solving circuit problems… Parallel Circuits I adds up V is constant 1 = 1 + 1 + 1 + ... Req R1 R 2 R 3 SERIES CIRCUIT I is constant V adds up R adds up
Circuit Breakers • Guards against overheating. It has a piece of wire that bends at high temps, causing a switch to “flip” which “opens” the circuit
Transformers Not these: These:
Transformers • Used to step up (increase) or step down (decrease) voltage through electromagnetic induction
Electromagnetic Induction • The process of inducing voltage by changing the magnetic field around a conductor
Power Transmission • Power can be transmitted very long distances at high voltages and low currents, it begins at 120,000 V at power plants and is stepped down until it reaches the 120 V used in your home
Electric Meter • Each month the number of kilowatt hours (kWh) is read and you are billed according to your usage
Magnetic Poles • Produce magnetic forces. • Every magnet has a North and South pole. • Opposite poles attract each other. Like poles repel.
Magnetic Fields • space around a magnet where a magnetic force is exerted • acts like an electric field
Magnetic Domains • The domain is determined by the alignment of the atoms in a magnet • A strong magnet has perfectly aligned atoms
The Earth’s Magnetic Field • A compass points to the earth’s magnetic field, however the geographic and magnetic fields are not perfectly aligned