There are 2 main circuit types: Series and Parallel.

--A circuit that has only 1 path for electrons to travel from a Power Source’s (-) to (+).

--Any break in the circuit’s conductors will stop the electrical current, since there is only 1 electrical path.

--Ex: old Christmas Lights— one light burns out, they all go out.

--A circuit that has multiple paths for electrons to travel from the Power Source’s (-) to the (+) pole.

-A break in a Parallel Circuit does not stop the electrical current because there is more than 1 way for electrons to reach the (+) end of the Power Source.

--Ex: New Christmas Lights continue to work, even if a light burns out since there are multiple ways for current to flow.

Moving electricity needs to work against friction in a wire—the more resistance in the wire, the more Power is needed to overcome the resistance from friction.

Ohm’s Law states that the speed of an electric current in a circuit is directly related to the Resistance and its Power/Voltage.

The Resistance in the Circuit is measured in Ohms

Using Ohm’s Law, you can calculate… A. How much resistance you need to control the voltage B. What speed (amps) the current will move C. How much voltage is needed to power a circuit.

The equation can also be used to find the initial Voltage IF the Resistance and Amps are known…

A. Needed Resistance (Ohms) = (Voltage / Amps) B. Needed Amps (A) = Voltage / Resistance C. Needed Voltage (V) = Amps x Resistance

The current in a hand-held video game moves at 0.5 A, with 120 V. What is the Resistance in this circuit?

Step # 1: list the knowns given from the problem…. Voltage = 120 V Amps/current = 0.5 A Resistance = ?

Step # 2: Use the proper equation to solve, and do the Math… Resistance = Voltage / Amps 120 / 0.5 = 24

Step # 3: add the proper unit to your answer…. So a Gameboy that runs on 120 Volts, 0.5 Amps needs 24 Ohms of resistance to work properly.

How much voltage would be needed if the circuits of a robot need at least 2 Amps of current speed to run through 100 Ohms of resistance?

Step #1: List the knowns… Voltage = ? Amps = 2 Resistance = 100 Ohms

Step #2: Use the proper equation and do the math… Voltage = Resistance x Amps 2A x 100 Ohms = 200

Step #3: Finish with the proper Unit A robot with 100 Ohms of resistance in the circuits, requiring 2 A of current needs 200 Volts of Electric power.

--Blueprint or technical drawing of a circuit. --Uses a standardized symbol system to show electrical plans of a circuit.

1. Conductor/Wire 2. Resistor 3. Bulb/lamp 4. Battery/DC source 5. Switch

When too much power enters a household circuit (Power Surge) the circuit has circuit breakers and fuses that protect appliances/wires from fires.

Electrical Heat is caused by the Friction of electricity’s moving electrons. High Amp electrical current can cause wires to melt and catch fire from the electrons’ Friction force being converted into heat energy.

1. Fuses Circuit conductor made from a thin metal strip with a low melting point.

Too much Electrical current/Friction will melt the fuse and break the circuit, stopping the electrical current.

2. Circuit Breakers Circuit conductor made from 2 different metals pressed together into a strip or use electromagnets.

High Electrical Current will cause the 2-metal strip to curl back, breaking the circuit, and switching off the power.

Electromagnetic breakers work when high current makes the magnet inside stronger and stronger until the magnet can pull the metal switch open.

Too much electrical energy can be transferred away from devices and people to protect them. This is called Grounding

Grounding a circuit gives electric current another path that carries the electricity to where it wants to be—the ground.

Lightning rods are placed on tall buildings to protect them from lighting strikes. An attached wire carries the current safely into the ground.

Some electrical plugs have a 3 rd prong that grounds them, and will carry electric current away in case of accidents.

Lastly, metal Faraday Cages can be used to protect sensitive devices from static electricity, and other current by absorbing, and sending current to the ground.