CHAPTER 6, SECTION 3
Series and Parallel Circuits: Lighten Up
HW: 6.3 PTG #1-9
• LO – Compare series and parallel
circuits and learn the language of electricity.
• 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
INVESTIGATE PART A• Electron Shuffle– 3 bulbs in parallel– Coulombs go to
• 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 3 if your bday is in Sept, Oct, Nov, Dec
• 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”
STUDENTS ANSWER...
• Pg. 615– #4a, b
INVESTIGATE PART A
• Electron Shuffle– 3 Volt battery– 1 Amp current
INVESTIGATE PART A
• Electron Shuffle– 1 Volt battery– 2 Amp current
STUDENTS ANSWER…
• Pg. 616– #7 a-e
HW: 6.3 PTG #1-9
• LO – Compare series and parallel
circuits and learn the language of electricity.
• 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
INVESTIGATE PART B
• #1-2 complete in groups, discussion• #3-4 complete in groups, show teacher• #5-6 complete in groups, show teacher,
discussion
PHYSICS TALK
• 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
PHYSICS TALK
• 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
PHYSICS TALK
• Series example:• 6 volt battery• How many joules will
each bulb get?
• Parallel Example• 6 volt battery• How many joules will
each bulb get?
PHYSICS TALK
• 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! • 9 Volt battery with a 3 amp current– Each bulb receives ____
joules of energy– Each bulb receives ____
amps of current
• 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.
PHYSICS TALK
• What is a resistor?
• What is voltage drop?
• A conductor that controls the current in a circuit.
• How many joules the coulomb drops off at each resistor
THE LANGUAGE OF ELECTRICITY
• 2 kinds of electric charges– Positive (protons)– Negative (electrons)
• Like charges (++ or - -) will repel
• Protons and electrons have opposite but equal charges– Protons (1+)– Electrons (1-)
THE LANGUAGE OF ELECTRICITY
• Electrons move in circuits and carry the electrical current delivering energy to the bulb
• Protons do not flow because they are locked within atoms
• Standard “package” of electric charge is called a Coulomb (C)=6.25 x 1018 electrons– Approximately the charge of a bolt of lightning!
THE LANGUAGE OF ELECTRICITY
• Standard rate of flow through a circuit is an ampere (A). – # coulombs that pass through a point in one
second
THE LANGUAGE OF ELECTRICITY• 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?
THE LANGUAGE OF ELECTRICITY
• Batteries or generators provide energy to the electrons (coulombs)
• Energy given to each coulomb is measured in Volts (V)
HOW DO WE DRAW CIRCUITS?
ESSENTIAL QUESTIONS PG. 620
• What does it mean?• How do you know?• Why should you care?
• LO and SC reflection
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