Upload
horace-johnston
View
222
Download
5
Tags:
Embed Size (px)
Citation preview
Electricity and Magnetism:Ac vs DC
Mr D. Patterson
Outcomes• distinguish between direct and alternating
currents and potentials, and apply Ohm’s law this will include applying the relationship:
DC• DC is an acronym for direct current• A direct current is formed when charges flow
in only one direction under the influence of an EMF
AC• AC is an acronym for alternating current• An alternating current is formed when charges
repeatedly change direction as they flow. This is formed by an EMF which alternates in polarity
The EMF source determines the current
Ohm’s law• Ohm’s law defines the relationship between
voltage, current and resistance.
• This can be applied to both DC and AC circuits
Ohm’s Law: DC
What is the current leaving the battery?
12 V
100 Ω
300 Ω
150 Ω
Ohm’s Law: ACWhat is the current leaving the
power source?
This question is not as straight forward as both voltage and current vary with time.
100 Ω
300 Ω
150 Ω
RMS values
Ohm’s Law: ACWhat is the current leaving the
power source?100 Ω
300 Ω
150 Ω