5.2 current and voltage
TRANSCRIPT
Brainiac http://www.youtube.com/watch?v=-n1pSHzdahc
5.2 Current and Voltage12 April 2023
What are the key words to do with
‘electricity’? Can you define them?
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
Current
Wh
at if
we
app
ly t
he
bra
kes?
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
Voltage
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