Level 7 physics: Telecommunications 2
As well as the overarching ideas and focus statements that underpin this particular programme, this section gives a set of example activities that are linked to various parts of the nature of science strand of the curriculum, showing how this strand can be embedded into the teaching programme.
Focus statements
- Electric fields are created when charges are created or the strength or direction of a magnetic field is changed. Magnetic fields are created by changing the strength or direction of electric fields.
- All electromagnetic radiation is caused by changing electric fields, changing magnetic fields, or both.
- Visible light is just a small part of the electromagnetic spectrum.
- An oscillating electron will emit an electromagnetic wave.
- Electromagnetic (EM) waves are the movement of electromagnetic energy. They don’t need a medium to travel through.
- All the energy we get from space comes in the form of electromagnetic waves, and they travel at c (3 x 10^8 m s^–1).
- Satellite communication is based on the controlled broadcast and reception of EM waves.
- The EM spectrum is the range of all possible frequencies (and wavelengths) of waves coming from an EM source, including sound waves, x-rays, etc.
- Visible light is a small part of the electromagnetic spectrum that is observable by the naked eye.
- Waves undergo certain phenomena, such as reflection, refraction, and diffraction.
- When light moves from an optically dense medium to a less dense one, if its angle of incidence exceeds the critical angle, it does not enter the second medium but bounces back into the first. This phenomenon is known as Total Internal Reflection (TIR).
- TIR is the principle behind fibre optics. It revolutionised the world of telecommunications, as it became possible to transfer information at c ( 3 x 10^8 m s^–1)
- Modern telecommunications (including the Internet) is built on the combination of 'broadband' fibre optics communication and satellite telecommunication (both forms of EM waves).
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Possible activities based on the NoS strand
Investigating in science
- Design an experiment or create a device that will show the relationship between the movement of a magnet and the creation of an electric current. Using your experiments or device, determine what other factors influence the relationship.
Communicating in science
- The terms khz, Mhz and Ghz are often applied to computers and electromagnetic radiation. Investigate whether these terms can apply to mechanical waves. Give examples of how and where such waves are used and, where possible, how they work.
- What are the scientific concepts underlying the following commonly used terms: digital technology, analogue technology, and wireless technology.
Participating and contributing
- Discuss the pros and cons for society of the use electromagnetic waves.
- Investigate the claims that the scientist Tesla believed that electricity could be distributed through the atmosphere without the need for wires.
- How and why does society today make so much use the digital transmission of information versus analogue transmission?
Understanding in science
- Use the following questions to explore optical fibre technology:
- What scientific theories and discoveries led to the development of optical fibres?
- Why is optical fibre transmission used so commonly today?
- How does digital transmission of information differ from older forms of transmission?
- Explore the concept of fields as defined by Michael Faraday’s explanation of forces between magnets and forces between electric charges. Show the effect these ideas had on our understanding of magnetic forces, electric forces and electromagnetic waves.
Discussion activities
- Compare the efficiency of electrical (telephone) communication and EM (fibre optic) communication.
Investigative experiments
- Investigate refraction through different media.
- Investigate TIR through a watertight pipe.
- Investigate wave pulse propagation through different media.
- Investigate a simple optical fibre and its use in telecommunications.
Community exercises
- Investigate a telecommunications device in operation (in the school or community).
- Interview a local telecommunications expert (from a local telecommunications company).
- Investigate the cost and plausibility of installing a school wide telecommunications system (intercom) or expanding the one already present.
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Possible assessments
Learning could be assessed using a variety of standards – for example:
- AS91169 Physics 2.2: Demonstrate understanding of physics relevant to a selected context (building a device) (3 credits, internal)
- AS91170 Physics 2.3: Demonstrate an understanding of waves (4 credits, external)
- AS901173 Physics 2.6: Demonstrate understanding of electricity and electromagnetism (6 credits, external)
Last updated December 14, 2012
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