7.3 voltage and current
TRANSCRIPT
http://www.youtube.com/watch?v=-n1pSHzdahc
7.3 Voltage and Current 12 December 2010
The cards have
keywords with more
scientific definitions,
can you match them
up?
The opposition to the flow of
current
The rate of flow of charge
How much energy each charge
carries
All components are in
a single branch
Components are in
multiple branches
Aims
• State the equations of current
and voltage in a series circuit
• Describe the changes in
current and voltage in a series
circuit
• Define current and voltage
For a series circuit:
321 IIII
The current is the same
throughout the circuit
Current is the rate of flow of charge
t
QI
Current
The number of
Coulombs flowing
past a point in the
circuit every second.
I = Q/t
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A
I’m counting
how many
coulombs of
electrons go
past me every
second
1 Amp = 1 coulomb per second
321 IIII
321 VVVV
For a series circuit:
321 VVVV
The total voltage is the sum
of the individual voltages
Voltage(emf)
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V
I’m checking the
difference in
energy (per
coulomb) between
the 2 red arrows
1 Volt = 1 Joule per coulomb
Voltage (p.d.)
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V
I’m checking the
difference in
energy (per
coulomb) before
and after the lamp
1 Volt = 1 Joule per coulomb
Voltage is the energy transferred per charge
Q
WV
321 IIII
321 VVVV
I have learned:
I have learned: