Topic: Electrical current
Abstract: The aim of this learning proposal is for students to understand the phenomenon of
electricity and how it has become an essential type of energy in our daily lives. Specifically, they will study electric current, Ohm’s Law and how current intensity varies in series circuits and parallel circuits of resistors. We will also consider why in our houses we have receivers connected in parallel.
Learning objectives:
1. To know or review the concepts of atoms and their charge.
2. To know the composition of electrical energy and its transformation into other types of
energy that can be used for human needs.
3. To know the electric current and Ohm’s Law.
4. To identify its magnitudes in everyday systems.
5. To represent physical phenomena in individual and collective dramatized action.
6. To mobilise linguistic, communicative, organisational and teamwork skills in order
to interpret together the concepts to be learnt.
Teachers’ profile: (team transversality)Technology, arts
Advisable age of students: 12-13 years old (Flexible according to the
curriculum of specific country)
Attention to diversity and inclusion aspects to have in account:
Previous knowledge:
– Lightning and thunder: Static electricity
– Ohm’s law: magnitudes and units. Connection types
Total duration: 2 hours approximately
Materials:
– Slide show with sound, showing lightning and thunder.
– Wrapper candy in two different colours.
– Cardboard, string, and markers to mark the electron charge, generator terminals,
– Yellow cloth or plastic bags or yellow cardboard of different colour intensities or neckerchiefs
Phase 1 Duration: 20 minutes approximately Visualisation
Development
1- Art showing different forms of energy
• Thunder and lighting
• Luminous
Can we associate these states with electrical energy?
(As an example we include below a priced photography)
2- Animations showing Ohm’s law:
For example: https://stickmanphysics.com/stickman-physics-home/unit-8-current-andcircuits/series-circuit/https://stickmanphysics.com/stickman-physics-home/unit-8-current-andcircuits/parallel-circuit/https://www.youtube.com/watch?v=84Kw3FXFeAw
Phase 2 Duration: 60 minutes approximately Artistic action and experimentation
Development:
1- Share and collect prior knowledge. Conversation and discussion among the students about what they know:
Are the pictures we have seen connected to each other?
From the animations: How can the same type of voltage produce different intensity? Why is it that when a bulb in the series circuit melts, no bulb works and in the parallel circuit it does?
2- In groups of 4 or 5 students explore and look for answers to previous questions and check their hypotheses.
3- Put the investigated elements together: Talk about the type of connection: series and parallel.
4- It will come out that:
• When the bulbs are in series they get the same current, but there’s a voltage drop between them (they illuminate less).
• The current in parallel is distributed in each branch. The voltage drop is the same as that of the battery. They illuminate more.
• If one bulb in the series circuit blows out, the circuit becomes open and the other bulb turns off.
• In houses we have parallel connections
5- Theatrical action:
The students will represent:
– 4 the static electrical components: resistors and battery with the indicator signs. The 3 resistors will wear a yellow t-shirt (or something yellow) indicating that there is a current.
– a switch to indicate initiation by rising with the hand an electric current initiation flag of any colour.
– The current carriers (electrical charges) to represent de electrical current
Representation 1.
A group of students who will play the role of current intensity will stand in a line evenly spaced in the class corridors representing the circuits. The circuit can have two branches, one with only one resistor and the other with two resistors.
When the student playing the on-off switch gives the starting signal, the students in the circuit will start the movement. They must move at the same pace, evenly spaced.
The pupils who do the current intensity will carry candy (energy). They will follow the circuit from one terminal of the battery to the resistors and then to the other terminal. The battery has a voltage of 3 volts.
In the first knot the students are divided (some go through branch 1
and some through branch 2).
– Branch 1: The students leave 3 candies on the resistor to represent the energy needed by the light bulb (or element that represents the resistor) to work.
– Branch 2: In the passage of the students through the first resistor they leave 1 candy (unit of energy) and the voltage drop is 1V. The passage of the students through the second resistor is bigger and they leave 2 candies. The voltage drop is 2 volts.
Representation 2.
– Series. One of the two bulbs stops working (the student representing it covers the yellow t-shirt with a black piece). The circuit is cut and no current is flowing, therefore the second bulb stops shinning as well.
– Parallel. One of the two bulbs stops working, but the current can go through the other brunch so the bulbs there keep working.
Phase 3: Duration: 20 minutes approximately Reflexion and debate
Development:
Students sit back in a circle and discuss the experience and what they understood from it, reviewing the concepts of current and voltage, the relationship between series and parallel connections.
References and links:
https://commons.wikimedia.org/wiki/File:Port_and_lighthouse_overnight_storm_with_lightning_in_Port-la-Nouvelle.jpg
Maxime Raynal. This file is licensed under the Creative Commons Attribution 2.0 Generic license
http://pfnicholls.com/Electronics_Resources/Video/Analogies.mp4
(Electronics Resources by Paul Nicholls is licensed under a Creative Commons Attribution 4.0 International License.)