Danger from electric shock
Lesson details
Learning outcome
I can describe mains electricity in the UK and the dangers of an electric shock.
Key learning points
- Mains electricity has a p.d. of 230 V between a live wire connection (230 V) and a neutral wire connection (0 V).
- Mains electricity has alternating current at a frequency of 50 Hz.
- Electric current passing through a person’s body can damage living tissue and/or stop their heart pumping blood.
- The size of current from a shock depends on the p.d. across the person and the resistance of their skin (I = V ÷ R).
- Wet skin has a much lower resistance than dry skin, and a smaller p.d. can cause a bigger current from a shock.
Keywords
Mains electricity - the electricity from electric sockets and circuits in a home
Live wire - a brown wire in a mains circuit that has a voltage of ±230 V
Neutral wire - a blue wire in a mains circuit that has a voltage of 0 V
Electric shock - a current passing through a person’s body that can be painful and sometimes harmful
Resistance - a property of materials that makes it harder for current to flow
Common misconception
Mains appliances draw all their electricity from the live wire, without need for a complete circuit.
Show pupils live and neutral wires connected to a AC connections on a power pack (you can use individual wires taken from mains cables) to show complete circuits are necessary, and that mains cables contain these wires.
Teacher tip
Ideas about mains electricity build on many different ideas covered in GCSE electricity topics. In this lesson, pupils consolidate their understanding of potential difference (between live and neutral wires) and encounter the equation I = V ÷ R in the context of electric shocks.
Content guidance
Depiction or discussion of sensitive content
Supervision
Adult supervision recommended
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.A battery provides DC, which stands for …
Q2.Which of the following equals a milliamp?
Q3.A series circuit contains a battery and some resistors only. The connections to the battery are swapped. Which of the following statements about the effect of this change is correct?
Q4.Which of the following statements is correct?
Q5.How many of the following are good electrical conductors? rubber, copper, tap water, sea water
Q6.One terminal of a power supply has a voltage of +5 V and the other terminal has a voltage of −2 V. Which of the following is the potential difference across the power supply?
Assessment exit quiz
6 Questions
Q1.Mains electricity is AC, which stands for …
Q2.What colour is the insulation of the neutral wire in a mains circuit?
Q3.What is the voltage of the live wire in a UK mains circuit?
Q4.Which of the following cause an electric shock?
Q5.Which of the following explains why it is much more dangerous to get an electric shock when your skin is wet than when your skin is dry?
Q6.A person gets an electric shock from the mains. Their skin has a resistance of 25 kΩ. The current through their body is A.
To help you plan your 11 combined science lesson on: Danger from electric shock, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 11 combined science lesson on: Danger from electric shock, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 combined science lessons from the Mains electricity unit, dive into the full secondary combined science curriculum, or learn more about lesson planning.