When someone grips the rope more tightly, they feel their hands getting warmer, and the rope gets harder to pull. The extra grip is increased resistance. The person’s hands being warmed is like energy being transferred out of the circuit. The person gripping the rope is like a bulb or a resistor. Strengths This model shows that all the charge is moving around the circuit at the same time, and it makes a link between resistance and energy transfer. Limitations If the person pulling the rope starts to pull harder when someone grips the rope more tightly, it could suggest that the battery works harder to keep the current the same when the resistance increases. Resource 4: Using models and analogies to teach electricity This resource is used in Activity 2. Table R3.1 identifies models and analogies being used and provides some suggestions for other models that might be helpful. Table R4.1 Using models and analogies to teach electricity. Section Activity Key teaching Sources of What models or analogies points/what do I want difficulty? are being used or might help students to learn from here? activity and related text? 12.1 Current (measured in Charge not Being used: Electric current as – amperes) is the flow of something that is a flow. Circuit is a continuous charge (measured in visible closed path any break stops – coulombs) per second the flow Confusion over Current measured by an electron flow Might also help: Rope model ammeter. Conventional direction and current flow is from + to conventional – current Current and electron drift through a conductor. Reconciling slow Current is instantaneous drift of electrons but drift speed is about 1 with instantaneous mm s–1 current Section Activity Key teaching Sources of What models or analogies points/what do I want difficulty? are used or might help students to learn from here? activity and related text?
When someone grips the rope more tightly, they feel their hands getting warmer, and the rope gets harder to pull. The extra grip is increased resistance. The person’s hands being warmed is like energy being transferred out of the circuit. The person gripping the rope is like a bulb or a resistor. Strengths This model shows that all the charge is moving around the circuit at the same time, and it makes a link between resistance and energy transfer. Limitations If the person pulling the rope starts to pull harder when someone grips the rope more tightly, it could suggest that the battery works harder to keep the current the same when the resistance increases. Resource 4: Using models and analogies to teach electricity This resource is used in Activity 2. Table R3.1 identifies models and analogies being used and provides some suggestions for other models that might be helpful. Table R4.1 Using models and analogies to teach electricity. Section Activity Key teaching points/what do I want students to learn from activity and related text? Sources of difficulty? What models or analogies are being used or might help here? 12.1 – Current (measured in amperes) is the flow of charge (measured in coulombs) per second Current measured by an ammeter. Conventional current flow is from + to – Current and electron drift through a conductor. Current is instantaneous but drift speed is about 1 mm s–1 Charge not something that is visible Confusion over electron flow direction and conventional current Reconciling slow drift of electrons with instantaneous current Being used: Electric current as a flow. Circuit is a continuous closed path – any break stops the flow Might also help: Rope model Section Activity Key teaching points/what do I want students to learn from activity and related text? Sources of difficulty? What models or analogies are used or might help here?
SS10_AIE_Final.docx