Transcript Electrical Flow Rate

Bell Ringer: 3.1A Data Sheet
You have fifteen minutes in your groups to
COMPLETE the data.
Notes on
Electrical Flow Rate
Electrical Rate: Page 82
Flow of electrons!
Electrical Current =
Charge moved
time interval
This is a measure of the amount of charge that flows through a
cross section of a conductor per unit of time
q
I=
t
Why can a bird
sit on the power line?
When does the current flow?
If there are voltage or potential difference,
then the current starts to flow from high
voltage to low voltage. But when a small bird
sits on the power line, both feet are on the
same voltage line!
Therefore, there are no potential
difference between these two feet.
D
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p
y
Why can a bird
sit on the power line?
Let's say the power line is very low, almost
touching the ground, and a chicken is trying to
cross it. If one leg is on the ground and the other
one is on the power line, then there are potential
difference between these two legs.
Therefore, there is a flow of charge
and eventually the chicken will be
barbequed like the diagram above.
D
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C
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p
y
Frequency (continue on 82)
How often something repeats itself!
Frequency =
f=
1
Number of cycles
time interval
And
T=
T
T = Period, the time it takes for one
complete cycle.
1
f
Quick Tips (continue on 82)
Ammeters measure current.
Ammeters are connected in series.
Voltmeters measure voltage.
Voltmeters are connected in parallel.
Mini Lab: Rate of Current (pg 81)
Question: Where is the rate of charge flow within a
simple circuit the greatest? The least? Or is it the
same everywhere?
Purpose: To determine location within a simple
circuit where the rate of charge flows is the greatest.
Materials: Compass, two D-cells, light bulbs, leads.
Reflection: Rate of Current
Page 81
Discussion: (top half of page)
Where was there the least amount of current?
How can you tell?
What factors contributed to that solution?
What did you learn?
Sketch: (Bottom half of page)
Make a colored sketch where you label all of
the parts.