Framework Physics 9
An Inquiry Based Science Teaching and Learning Framework
Topic/Learning Activity
Investigating electricity - d.c. and a.c. OP54
Student Cohort
Student Level
2nd/3rd year students who have already covered basic electricity.
Prior Knowledge
Basic knowledge of conductors, voltage, current, circuit diagrams/symbols.
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Stimulus to Engage
Play a short clip from any song by the band AC/DC.
Ask do they know the name of the band.
Ask do they know what the letters in the band’s name stand for.
Use pHET to demonstrate a.c. and d.c. circuits.
Science Questions
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What is the difference between d.c. and a.c.?
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Does this difference have any effect on the circuits that we set up?
Learning Outcomes
Content Knowledge:
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Recall that the mains voltage is 230V a.c.
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State what the letters d.c. and a.c. stand for
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Identify the symbols for d.c. and a.c.
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Be able to tell the difference between a.c. and d.c.
Process:
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The students will set up different circuits to see if they will conduct with both d.c. and a.c.
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The students will classify objects into those that use a.c. or d.c. power source
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The students will investigate using pHET the difference between a.c. and d.c.
Skills:
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Ability to set up the required circuits to see if current will flow
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Work with a team and communicate with each other within a team
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Framework Physics 9
An Inquiry Based Science Teaching and Learning Framework
Questions during Activity
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Is there any difference in appearance of a d.c. source (battery) as
compared to an a.c. source (power pack)?
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Is there any difference if we set up a circuit with a bulb and supply current
from a d.c. source and then an a.c. source?
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Is there any difference if we set up a circuit with a buzzer and supply
current from a d.c. source and then an a.c. source?
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Is there any difference if we set up a circuit with an LED and supply current
from a d.c.source and then an a.c. source?
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What is the difference between them?
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■■ Pupils could use a voltage sensor with a datalogger/computer to look at d.c. and a.c.
An oscilloscope may also be used.
Developing the Activity
The topic could be taken further by:
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Demonstrating how a.c. is changed to d.c. using a rectifier and linking this to
the diode in the electronics section
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Discussing why is it that the ESB use a.c. instead of d.c. when transporting
electricity around the country, thus leading to the idea of transformers
Reflecting Back to Learning Outcomes:
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Do I know what the letters a.c. and d.c. mean and recognise their symbols?
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Do I understand what d.c. is?
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Do I understand what a.c. is?
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Do I understand the difference between them?
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Can I set up a circuit to show this difference?
Additional Resources
Stimulus materials, websites, etc.:
Oscilloscope, rectifiers, bicycle dynamo
How has the use of ICT enhanced the learning?
A voltage sensor used with a datalogger or computer is very simply set up - far easier than using an
oscilloscope.
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