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Current Electricity 10 November 2024 Recap activity: Complete the symbols handout Learning Focus: What happens to the electric current at a junction in the circuit? What...

Current Electricity 10 November 2024 Recap activity: Complete the symbols handout Learning Focus: What happens to the electric current at a junction in the circuit? What is potential difference and how do you measure it? 1-3 Identify common symbols for components. 4-6 Describe how changing the number or type of components in a circuit affects the current. 7-8 Describe how current and voltage behave in series and parallel circuits. 9 Describe the relationship between watts and joules/second. Can you guess the key word? Can you guess the key word? Can you guess the key word? Can you guess the key word? Can you guess the key word? 10/11/2024 Introduction to Electrical Circuits Starter Activity: No. Symbol Name and Function 1 Light Matchbulb the–symbol Gives out light. to its name and function. 2 Cell – Pushes charges around a circuit. 3 Battery – 2 or more cells. 4 Wire – connects circuit parts. 5 Switch – turns current on and off. 6 Voltmeter – measures potential difference (voltage). 7 Ammeter – measures electric current. 10/11/2024 Introduction to Electrical Circuits Starter Activity: No. Symbol Name and Function 1 Light Matchbulb the–symbol Gives out light. to its name and function. 2 Cell – Pushes charges around a circuit. 3 Battery – 2 or more cells. 4 Wire – connects circuit parts. 5 Switch – turns current on and off. 6 Voltmeter – measures potential difference (voltage). 7 Ammeter – measures electric current. Circuit Symbols Discuss with your partner what you think each of the circuit symbols represents. Lamp Battery Cell Switch Voltmeter Ammeter Resistor Motor The charges that flow around a circuit are called electrons. Electrons are negative, so they flow AWAY from the negative side of the cell/battery, TOWARDS the positive side. What is an KEYWORDS: electric Current? Electrons An electric ……………… current is a Flows flow of ……………………, electrons which Current are negatively charged Circuit particles. An electric ………………… Particles flows when current only …………… EXTENDING: The there is a complete wires in a circuit are circuit often made of …………… for the current. copper. Explain why this material is used. Series and Parallel Circuits Can you remember the difference between series and parallel? End  Copy down the following key words and their definitions: Series Circuit- A circuit where there is only one route the current can take around. Parallel Circuit- A circuit where there are junctions that allow the current to take different routes. Extending: Draw a circuit diagram for each to go with your definition. Extending: Draw a circuit diagram for each to go with your definition.  There are 2 types of circuits. Series Parallel Only 1 pathway for the electrons to 2 or more pathways for electrons to flow. flow. It is cheaper as they use less power. It is more expensive as they use more If 1 part of the circuit breaks, the circuit power. won’t work. If 1 bulb breaks the other will stay on. Current We use an ammeter connected in series to measure the current flowing through a circuit. The units for current are amperes (A).  What is current? Current is the rate of flow of charge. Millions of electrons flow through the bulb in a torch each second, when the switch is closed. If more electrons flow through the bulb each second, the current is higher. If less electrons flow through the bulb each second, the current is lower. Current is measured in amperes (A), using an ammeter. Current Investigation Developing Securing Exceeding Developing AND Developing AND Construct describe what you write down each the circuits notice about current in of the ammeter above. series and parallel readings. circuits.  Current Electricity 10 November 2024 Do now: 1) What is current measured in? 2) How might we measure current? 3) Describe the difference between series and parallel circuits? 4) Explain what an electric current is. 1-3 Identify common symbols for components. 4-6 Describe how changing the number or type of components in a circuit affects the current. 7-8 Describe how current and voltage behave in series and parallel circuits. 9 Describe the relationship between watts and joules/second.  Answers 1. What is current measured in? Current is measured in amperes (A). 2. How might we measure current? We can measure current using an ammeter, which is connected in series with the circuit in order to measure how much current is flowing. 3. Describe the difference between series and parallel circuits: Series circuit: All components are connected one after another in a single loop. If one part stops working, the whole circuit stops working. Parallel circuit: Components are connected in separate branches. If one branch stops working, the other branches still continue to work. 4. Explain what an electric current is: Electric current is the flow of electrical charge (usually electrons) through a wire or circuit. It is what makes electrical devices work. Current The current is the same everywhere in a series circuit. The current splits when it comes to a junction in a parallel circuit. Building Circuits 0.45 Building Circuits 0.45 0.45 0.45 The current is the same. Building Circuits 1.80 Building Circuits 1.80 0.9 0.9 1.80 The current in a parallel circuit is shared between the pathways. The total current is higher than in a series circuit.  Voltage - Electricity 10 November 2024 Do now: 1) What is current measured in? 2) Is current the same or different in a series circuit? 3) Is current the same or different in a parallel circuit? 4) Explain what an electric current is. 1-3 Identify common symbols for components. 4-6 Describe how changing the number or type of components in a circuit affects the current. 7-8 Describe how current and voltage behave in series and parallel circuits. 9 Describe the relationship between watts and joules/second. Building Circuits 0.45 0.45 0.45 The current is the same. Building Circuits 1.80 0.9 0.9 1.80 The current in a parallel circuit is shared between the pathways. The total current is higher than in a series circuit. Voltage Voltage across a component is a measure of the energy transferred by that component. We use a voltmeter, connected in parallel, to measure voltage. The units for voltage are volts (V).  What is potential difference (voltage)? Potential difference is also called voltage. Potential difference is the amount of energy transferred between 2 points in a circuit. Potential difference is measured in volts (V) using a voltmeter. A higher voltage means more energy is transferred. Voltmeters are always connected in parallel. Voltage Investigation Developing Securing Exceeding Developing AND Developing AND Construct describe what you write down each the circuits notice about voltage in of the voltmeter above. series and parallel readings. circuits. Voltage In a series circuit the voltage across all the components add up to the voltage across the cell. In a parallel circuit the voltage across each branch of the circuit is the same as the voltage provided by the cell.  Building Circuits 1. Draw a symbol diagram for a series circuit made up of 1 bulb and a cell. 2. Draw a symbol diagram for a series circuit made up of 2 bulbs and a cell. 3. What do you notice about the brightness of the bulbs, when more When more light bulbs are added in series, are added to a series the brightness of the lightbulbs decreases circuit? (they get dimmer).  Building Circuits 1. Draw a symbol diagram for a series circuit made up of 1 bulb and a battery. 2. Draw a symbol diagram for a parallel circuit made up of 2 bulbs (1 lightbulb on each branch) and a battery. 3. What do you notice about the brightness of the bulbs, when more are When more light bulbs are added in parallel, the brightness of the light bulbs stays the added to a parallel circuit? same. Building Circuits 9 Building Circuits 9 4.5 4.5 The voltage in a series circuit is shared between the components. Building Circuits 9 Building Circuits 9 9 9 The voltage is the same across the branches. Copy the circuit drawing below and add in the missing ammeter/voltmeter readings: Extending: Draw a parallel circuit with ammeter and voltmeter readings.  End Tasks: 10 minutes Developing Securing Exceeding Complete Complete Complete worksheet worksheet worksheet 9Jc-1 about 9Jc-5 all 9Jc-7 all current about current about power. electricity. and voltage. Extending: Describe a model that could be used to represent electricity (including current and voltage). Spot the Mistake You will be shown several images of circuits. On your mini whiteboard write down what is wrong with the picture. EXTENDING: Draw a corrected version of the circuit. Spot the The two negative terminals on the cells Mistake are connected together. Spot the The current in a series circuit is the same at Mistake every point. Spot the There is no power Mistake source. Spot the One of the bulbs has blown- the circuit will Mistake not work. Spot the The two negative terminals have been Mistake connected together. Spot the The switch is open, Mistake there will be no current.