Download Series Circuits Series Circuit: a circuit that has only one path for

Series Circuits
Series Circuit: a circuit that has only one path for current to travel
- in other words, electrons have only one pathway to travel through a series circuit
-if switch is opened, all electrons are blocked and the current stops
Think of people using a waterslide. There is only one single path for everyone to follow. Everyone
must walk up the same stairs in order to gain potential energy and then use the slide to use that
potential energy. If one person stops then everyone must stop.
Voltage in a Series Circuit - the charge that leaves a 12V battery “loses” all 12 V before it returns to
the battery
-these losses occur on loads such as light bulbs or resistors, which transform the electrical energy into
other forms of energy
-each load in the series circuit loses a portion of the total voltage supplied to the electrons by the
battery
- the sum of the voltages lost on the loads equals the total voltage supplied by the battery
Thinking of the waterslide example. People use
all the potential energy they gained by walking
up the stairs. They cannot stop in the middle of
the slide.
Current in a Series Circuit: in an electric circuit the electrons repel each other (to some degree)
-therefore most of the electrons flowing in a circuit remain fairly evenly spaced apart
- since there is only one path for the electrons to travel in the series, the current in each part of a
series circuit is equal
Think of a garden hose, the amount of water
entering, must be the same as the amount of
water leaving.
Resistors in Series Circuit: when you place resistors in a series you increase the total resistance and
therefore the total current throughout the circuit decreases
Think of the waterslide example. If there was a dry patch that slowed people on the slider (like a
resistor), then everyone else behind them would have to slow down as well to wait for the slow
people. If you added more dry patches it would slow down more people, and then everyone
behind will have to slow down even more.
Key Points
1) The current is the same everywhere in the circuit
2) The voltage is separated between each load depending on resistance. But the total voltage
across all the loads must be equal to the amount of voltage leaving the battery
3) Adding resistors, increases the total resistance, and therefore the total current of the circuit
decrease
Parallel Circuits
Parallel Circuit: a closed pathway that has several different paths
- electrons leaving the battery have more than one possible way of returning to the battery.
Think of people using a waterslide. Think of there being more than one slide. If someone decided to
stop on one pathway, the other pathways are still operational.
Voltage in a Parallel Circuit: In an electric circuit, the battery supplies electric potential energy to the
electrons through a potential difference
- the electrons will lose all the potential energy before returning to the battery
- Loads that are in parallel have the same voltage
Thinking of the waterslide
example. Regardless of which
slide a person chooses, they all
end up in the same pool at the
end. They will "lose" all the
potential energy they gained
by climbing the stairs by the
time they reach the bottom.
Current in a Parallel Circuit: the current branches into different pathways that eventually rejoin. A
portion of the electrons travels on each path.
- a pathway with less resistance will be able to have more electrons travel on it, therefore will have a
greater current
-Junction point is the location where a circuit divides into multiple paths or where multiple paths
combine
- The total current entering a junction point must equal the sum of the current leaving the junction
point
Think of the waterslide example.
The amount of people in each slide
will differ. With less resistance, the
flow of people is much greater,
and therefore more people can
travel on that slide. But the total
amount of people that enter the
slides must equal the total amount
of people leaving the slides.
Resistors in Parallel Circuit: when you place resistors in parallel with another resistor, you create
another pathway so total resistance must decrease
- when the total resistance of the circuit decrease, the total current leaving the battery must
therefore increase.
Think of a long line in a grocery store. If there is only one cashier open, there is only one path and
there is a long wait. If you added more cashiers, customers can choose either line, and although
they will still have to wait, it will be much shorter.
Key Points
1) Voltage is the same over each separate load
2) Current entering a junction point must equal the sum of currents leaving a junction point
3) Adding more pathways (resistors or loads) actually decreases the total resistance
4) When decreasing the overall resistance, the current must increase