even more about electricity. circuits circuits there are two kinds of circuits: there are two kinds...
TRANSCRIPT
Even MORE about
ELECTRICITYELECTRICITY
CircuitsCircuits
CircuitsCircuits
• There are two kinds of circuits:There are two kinds of circuits:
CircuitsCircuits
• There are two kinds of circuits:There are two kinds of circuits:
1.1.SeriesSeries
CircuitsCircuits
• There are two kinds of circuits:There are two kinds of circuits:
1.1.SeriesSeries2.2.ParallelParallel
Series CircuitSeries Circuit
Series CircuitSeries Circuit
• In a series circuit there is only one pathway for electrons to follow.
Series CircuitSeries Circuit
• In a series circuit there is only one pathway for electrons to follow.
Series CircuitSeries Circuit
Series CircuitSeries Circuit
Series CircuitSeries Circuit
Series CircuitSeries Circuit
Series CircuitSeries Circuit
Series CircuitSeries Circuit
• In a series circuit when the power is turned off, everything goes off.
Series CircuitSeries Circuit
• In a series circuit when the power is turned off, everything goes off.
Parallel CircuitParallel Circuit
Parallel CircuitParallel Circuit
• A parallel circuit is one where electrons have A parallel circuit is one where electrons have more than one more than one path to follow.path to follow.
Parallel CircuitParallel Circuit
• A parallel circuit is one where electrons have A parallel circuit is one where electrons have more than one more than one path to follow.path to follow.
Parallel CircuitParallel Circuit
Parallel CircuitParallel Circuit
Parallel CircuitParallel Circuit
Parallel CircuitParallel Circuit
• In p.c. one device can be turned off In p.c. one device can be turned off without affecting the others.without affecting the others.
ResistanceResistance
ResistanceResistance
• In electrical circuits In electrical circuits resistorsresistors are used to are used to reduce the currentreduce the current..
• The unit used to measure resistance is The unit used to measure resistance is ohmsohms..• The symbol is The symbol is ΩΩ
Question: How do we figure out Question: How do we figure out what the resistance is? what the resistance is?
Question: How do we figure out Question: How do we figure out what the resistance is? what the resistance is?
Answer:Answer:
OHM’S LAWOHM’S LAW
Ohm’s LawOhm’s Law
• Ohm’s Law says that as you increase voltage, Ohm’s Law says that as you increase voltage, current also increases. As you increase the current also increases. As you increase the resistance, current decreases.resistance, current decreases.
Ohm’s LawOhm’s Law
• Ohm’s Law says that as you increase voltage, Ohm’s Law says that as you increase voltage, current also increases. As you increase the current also increases. As you increase the resistance, current decreases.resistance, current decreases.
• In other words...In other words...
Ohm’s LawOhm’s Law
• Ohm’s Law says that as you increase voltage, Ohm’s Law says that as you increase voltage, current also increases. As you increase the current also increases. As you increase the resistance, current decreases.resistance, current decreases.
• In other words...In other words...
Ohm’s LawOhm’s Law
V = I x RV = I x R (V)volts, (I)amps, (R)ohms(V)volts, (I)amps, (R)ohms
Ohm’s LawOhm’s Law
Practice ProblemsPractice Problems
V = IRThe starter motor of a car is connected to a 12V The starter motor of a car is connected to a 12V
battery. If the starter motor has 75A of battery. If the starter motor has 75A of current going through it to start the car, what current going through it to start the car, what is the resistance of the starter motor?is the resistance of the starter motor?
Practice ProblemsPractice Problems
V = IRThe starter motor of a car is connected to a 12V The starter motor of a car is connected to a 12V
battery. If the starter motor has 75A of battery. If the starter motor has 75A of current going through it to start the car, what current going through it to start the car, what is the resistance of the starter motor?is the resistance of the starter motor?
R = V/IR = V/I
Practice ProblemsPractice Problems
V = IRThe starter motor of a car is connected to a 12V The starter motor of a car is connected to a 12V
battery. If the starter motor has 75A of battery. If the starter motor has 75A of current going through it to start the car, what current going through it to start the car, what is the resistance of the starter motor?is the resistance of the starter motor?
R = V/IR = V/IR = 12V/75A
R = 0.16Ω
Practice ProblemsPractice Problems
V=IRV=IRA flashlight has a filament with a resistance of A flashlight has a filament with a resistance of
10.7 10.7 ΩΩ. The batteries provide 2.8V. What is . The batteries provide 2.8V. What is the current through the filament?the current through the filament?
Practice ProblemsPractice Problems
V=IRV=IRA flashlight has a filament with a resistance of A flashlight has a filament with a resistance of
10.7 10.7 ΩΩ. The batteries provide 2.8V. What is . The batteries provide 2.8V. What is the current through the filament?the current through the filament?
I = V/R
Practice ProblemsPractice Problems
V=IRV=IRA flashlight has a filament with a resistance of A flashlight has a filament with a resistance of
10.7 10.7 ΩΩ. The batteries provide 2.8V. What is . The batteries provide 2.8V. What is the current through the filament?the current through the filament?
I = V/RI = 2.8V/10.7Ω
I = 0.26A
The End... for now