“Introduction to Circuits” Unit 10 Part 1: “Introduction to Circuits” Go over Unit 10 Rubric!

Using the materials provided to your group… “Light The Bulb” Using the materials provided to your group… See if you can make the light bulb light in 4 different ways. You have 5 minutes!!! MIT graduates attempt...

CIRCUIT CHALLENGE MIT graduates attempt...

Current vs. Static Electricity In current electricity, electrons are continuously moving; different from static Because the charges are flowing (moving), they have the ability to do work

Electron Flow through a Lightbulb

Electrons flow in a circular path from positive to negative Electric current in a circuit + Electrons flow in a circular path from positive to negative

Basic Parts of a Circuit Source of electric energy (battery or wall outlet) Wires Device that uses the energy (light bulb, etc.)

Circuit Symbols Resistor Battery Voltmeter Light bulb Wire Ammeter Any object that uses the energy Voltmeter Measures voltage between 2 points, placed in parallel, very high resistance Ammeter Measures current, placed in series, very low resistance Battery Energy source Light bulb Wire A conductor that provides a path for the electrons to travel along Switch Controls whether the circuit is open or closed V1 A1

In order for electricity to move through a circuit it must be closed Open or Closed? http://phet.colorado.edu/new/simulations/sims.php?sim=Circuit_Construction_Kit_DC_Only In order for electricity to move through a circuit it must be closed If a circuit is open then the electricity cannot flow Switches are objects that are used to determine whether a circuit will be closed or opened open

“Describes the relationship between Voltage, Current & Resistance” Ohm's Law “Describes the relationship between Voltage, Current & Resistance” Current (Amps) Voltage (Volts) V I R = x Resistance (Ohms or Ω) “For a given resistance, the voltage is proportional to the current flow.”

Voltage (V) Def : the energy each electron has to move it through a circuit to do work Unit: Volts (V) Symbol: V

Voltage If = 1.5 volts 6 V ?V 3.0V

Current (I) Def : the number of electrons passing a point per second in a circuit; “Rate of flow” Unit: Amperes (amp) Symbol: I It is measured using an ammeter A

Resistance is the opposition to the flow of charge Symbol: (R) Unit: ohm (Ω) Measured by an ohmmeter Ω

“Describes the relationship between Voltage, Current & Resistance” Ohm's Law “Describes the relationship between Voltage, Current & Resistance” Current (Amps) Voltage (Volts) V I R = x Resistance (Ohms or Ω) “For a given resistance, the voltage is proportional to the current flow.”

Questions: Sample problems: A fluorescent light draws 0.25 amps of current when connected to a 120 V source. What is the resistance of the light? What voltage is needed to cause a current of 50 amps through a resistance of 20 ohms? What happens if we have two or more light bulbs connected?

Mini-Project: Due Before Final Students in Mr. Penmoon class just happened to be nominated to work with the Lord of the Ring team for the up coming season in ‘’the land of the lord of the ring” where there is no electricity. Our task is to use our knowledge to help them harvest the energy from the sun. “Concept of Photoelectric Effect” We need to come up with the plan. We need to know how much energy is needed daily for work. And what type of circuit (series or parallel) to implement for the most efficient.

R Current (Amps) Voltage (Volts) Resistance (Ohms or Ω) Ohm's Law I V http://phet.colorado.edu/new/simulations/sims.php?sim=Ohms_Law Current (Amps) Voltage (Volts) Resistance (Ohms or Ω) I V R = /

What is the voltage of this battery?