Series and Parallel Circuits: Lighten Up

LO LO – Compare series and parallel circuits and learn the language of electricity. SC SC – Compare series and parallel circuits – Recognize generator output limit – Modify the Electron-Shuffle model of electricity Do Now: – Copy LO and SC on new left side page – WDYS/WDYT pg. 614 Agenda: – Do Now – Investigate Part A

Electron Shuffle Electron Shuffle – 3 bulbs in parallel – Coulombs go to Light Bulb 1 if your bday is in Jan, Feb, Mar, Apr Light Bulb 1 if your bday is in Jan, Feb, Mar, Apr Light Bulb 2 if your bday is in May, June, July, August Light Bulb 2 if your bday is in May, June, July, August Light Bulb 3 if your bday is in Sept, Oct, Nov, Dec Light Bulb 3 if your bday is in Sept, Oct, Nov, Dec 1-volt battery=1 Joule per Coulomb 1-volt battery=1 Joule per Coulomb – Battery: “The battery Voltage is 1 Volt, which equals one joule of energy for each coulomb” – Coulomb: “One coulomb of energy receiving one joule of energy” – Light Bulb: “I just received 1 Joule of energy from that coulomb”

Pg. 615 Pg. 615 – #4a, b

Electron Shuffle Electron Shuffle – 3 Volt battery – 1 Amp current

Electron Shuffle Electron Shuffle – 1 Volt battery – 2 Amp current

Pg. 616 Pg. 616 – #7 a-e

LO LO – Compare series and parallel circuits and learn the language of electricity. SC SC – Compare series and parallel circuits – Recognize generator output limit – Modify the Electron-Shuffle model of electricity Do Now: – What happened to the brightness of the bulbs in a parallel circuit when compared to the bulbs in series circuit? Agenda: – Do Now – Investigate Part B

#1-2 complete in groups, discussion #1-2 complete in groups, discussion #3-4 complete in groups, show teacher #3-4 complete in groups, show teacher #5-6 complete in groups, show teacher, discussion #5-6 complete in groups, show teacher, discussion

Series Circuit Series Circuit Total voltage of the battery is divided equally between all bulbs in the circuit. Coulombs of charge must go through each bulb and drop off joules of energy. If one bulb is removed, the circuit is open and ALL the bulbs will go out. 1 volt battery, each bulb will receive 1/3 Bulbs will appear dimmer

Parallel Circuit Parallel Circuit Total voltage provided to each bulb is equal to the voltage of the battery. Each bulb has a complete circuit from the battery to the bulb and back to the battery If one bulb is removed, others will remain lit Bulbs will be equally bright. Battery will run out more quickly

Series example: Series example: 6 volt battery 6 volt battery How many joules will each bulb get? How many joules will each bulb get? Parallel Example 6 volt battery How many joules will each bulb get?

What about the current in a parallel circuit? What about the current in a parallel circuit? Current (coulombs/sec) is divided in a parallel circuit Example: If a parallel circuit has a 3 amp current, each bulb gets one amp of current How much current would each bulb get if it was a 9 amp circuit?

Put it all together! Put it all together! 9 Volt battery with a 3 amp current – Each bulb receives ____ joules of energy – Each bulb receives ____ amps of current

Put it all together! Put it all together! 9 Volt battery with a 3 amp current – Each bulb receives __9__ joules of energy – Each bulb receives __1__ amps of current – One coulomb will pass each resistor (bulb) every second and drop 6 volts there.

What is a resistor? What is a resistor? What is voltage drop? What is voltage drop? A conductor that controls the current in a circuit. How many joules the coulomb drops off at each resistor

2 kinds of electric charges 2 kinds of electric charges – Positive (protons) – Negative (electrons) Like charges (++ or - -) will repel Like charges (++ or - -) will repel Protons and electrons have opposite but equal charges Protons and electrons have opposite but equal charges – Protons (1+) – Electrons (1-)

Electrons move in circuits and carry the electrical current delivering energy to the bulb Electrons move in circuits and carry the electrical current delivering energy to the bulb Protons do not flow because they are locked within atoms Protons do not flow because they are locked within atoms Standard “package” of electric charge is called a Coulomb (C)=6.25 x Standard “package” of electric charge is called a Coulomb (C)=6.25 x electrons – – Approximately the charge of a bolt of lightning!

Standard rate of flow through a circuit is an ampere (A). Standard rate of flow through a circuit is an ampere (A). – # coulombs that pass through a point in one second

Resistance is the opposition to the flow of electric charge Resistance is the opposition to the flow of electric charge – Resistors are objects that oppose flow of electric charge (light bulb) – Example: High resistance-Tungsten filaments in light bulbs glow as they “rob” energy from passing electrons, causes the tungsten to get hot and glow=LIGHT! – Example: Low resistance-copper wire, electrons transfer little energy so we use copper to conduct electricity in circuits – Measured in Ohms (Ω) – Was the steel wool high or low resistance? Why?

Batteries or generators provide energy to the electrons (coulombs) Batteries or generators provide energy to the electrons (coulombs) Energy given to each coulomb is measured in Volts (V) Energy given to each coulomb is measured in Volts (V)

What does it mean? What does it mean? How do you know? How do you know? Why should you care? Why should you care? LO and SC reflection LO and SC reflection