Physics / Science GCSE: Circuits: Investigate I–V characteristics of circuit elements such as filament lamp, diode and resistor at constant temperature
This video focuses on a GCSE required practical included in AQA, Edexcel and OCR specifications.
This video reinforces several circuit symbols and also how to setup circuits to measure potential difference across and current through several circuit elements.
It then explores the IV characteristics, as sketch graphs, for three circuit elements.
The practical allows development of Apparatus & Techniques Physics 6 & 7 (DfE GCSE subject content guidance, Appendix 4).
This video could be used before or after students’ own investigations and could be used to describe how to set up the graphs or as an opportunity to revisit.
Showing the IV characteristics as sketch graphs, rather than actual plotted graphs, should help students to recognise and explain the shape of each graph without being distracted by axes and values.
If using a revision, the video could be paused at the stage before each graph is displayed and ask students to sketch the graph, or to match the three graphs to the three different components.
Improvements are suggested, importantly, including the explanation of how that would improve the investigation.
Points for discussion:
Students often find electricity concepts challenging generally and so familiarity with circuits and how diagrams relate to practice is important.
The graphs produced from students’ own results don’t always look like the theoretical graphs which in itself provides a challenge but it is important that as well as knowing how to investigate I-V characteristics, students can recognise and explain the expected graphs.
The video also focuses on specific improvements, which students often find challenging.
Language of science such as anomaly and resolution are highlighted as part of the discussion around improvements.
Students should be encouraged to draw circuit diagrams whenever describing any of these investigations.
Familiarity with circuit symbols and the basics of setting up circuits will help students to recall this investigation but also then apply to unfamiliar contexts.
Suitable for teaching Chemistry and Combined Science at Key Stage 4 and GCSE in England, Wales and Northern Ireland, and at National 4 and 5 in Scotland.