To understand how fuses and circuit breakers work. 21 September 2018 Fuses and Circuit Breakers Objectives To understand how fuses and circuit breakers work. HSW: AF2 – Understanding the applications and implications of science Used before in: lesson 1 – household electricity Will use again in: lesson 3 – fuses and circuit breakers PLTS: Team workers – Work collaboratively with others. Keywords: Fuse, RCCB, Earth, double insulation, diameter, electromagnet, current, resistance Question: Why don't birds get electrocuted on power lines? Answer: http://www.youtube.com/watch?v=rN3QhtnlCSw

Outcomes All students should be able to recall how a fuse works and that there are different types of fuse and state that circuit breakers are safer than fuses. Most students should be able to describe how a fuse works and they are different to circuit breakers. Some students should be able to explain how circuit breakers work and why they are safer than fuses.

Fuses and Circuit Breakers

Current when RED HOT (A) Current just before MELTS (A) Fuses Investigation Results Analysis Plot a graph of each Current (in Amps) on the y-axis and Diameter on the x-axis (in mm). You will have two lines on one graph – label them. Wire Diameter (mm) Current when RED HOT (A) Current just before MELTS (A) 0.355   0.315 0.274 0.234 0.193 0.152

Conclusion and Evaluation Which would be the best piece of wire to be a 3A fuse? Explain your answer. Write an evaluation explaining (a) if this was the best way to carry out the experiment. (b) Were there any things you would change if you were to do this again? (c) Explain any further tests you would carry out to back up your conclusion.

Tell me two things... (for each) that you have done well this session that you know now that you didn’t know at the start that you could do better next time that you would like to know more about 2