Chapter 1: Principles of electrical science Activity sheet 1.5: SI units Aims and objectives At the end of this activity, students should be able to: ● recognise base units ● recognise the main derived units used by a building services engineer. Suggested delivery 1. Give the students 30 minutes to complete the activity sheet in pairs. 2. Ideally the students will complete the first draft in pencil, mark it and then correct it in pen, keeping a good copy for their notes. 3. Instruct the students to complete the missing gaps on the whiteboard in teams using the PowerPoint™ template. Once completed, the students must create their own version and laminate it for their personal file/notes. Equality and diversity opportunity Discuss the origin of some of the symbols used, such as resistance and Ohm (German scientist, Georg Ohm, and a Greek letter). Stretch Encourage the students to identify a wider range of relevant units, symbols and descriptions using the Internet/supplied material. © Pearson Education Ltd 2013. Copying permitted for purchasing institution only. This material is not copyright free. 1 Chapter 1: Principles of electrical science Term Symbol Unit name Unit Symbol Electric current I ampere A Definition A quantity (Q) of electricity crossing a section of conductor in a time (t); commonly referred to as current flow. Potential difference Resistance Resistivity Temperature Mass Force Magnetic flux Magnetic flux density Frequency Power Energy Time Length Area 2 © Pearson Education Ltd 2013. Copying permitted for purchasing institution only. This material is not copyright free.