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| Chapter 7: Electricity for Everyone |
| Activity Summaries |
Physics Principles |
Activity One: Generate
Students investigate electrical energy and electric circuits with a simple hand generator, wires, and bulbs. Using the hand generator introduces the concept that electricity is the result of converting one form of energy into another. |
- Energy conservation
- Electricity
- Mechanical energy
- Series and parallel circuits
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Activity Two: Lighten Up
An experiment in which students compare the relative brightness of light bulbs in series and parallel circuits and increases their understanding of energy flow necessary in generating electricity. They also learn that a generator has a limit of what it can support. Students also read to learn more about electrical energy. |
- Energy conservation
- Electricity
- Mechanical energy
- Series and parallel circuits
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Activity 3: Ohm’s Law
Students calculate the resistance of an unknown resistor given the potential drop and current, construct a series circuit, properly use a voltmeter and ammeter in a series circuit, and graph the relationship between voltage and current for a resistor that obeys Ohm’s Law.
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- Ohm’s Law
- Voltage, Current, Resistance
- Series and Parallel circuits
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Activity Four: Load Limit
To experience load limit, students add bulbs to their simple circuit until the load is exceeded. They then calculate the load limit of a household circuit and watts required by appliances, comparing these to the limits given in the challenge. This also introduces use of terms and equations for calculating power. |
- Watts, voltage, currents
- P=IV
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Activity Five: Who's In Control?
Students again assemble a parallel circuit to explore how switches control the flow of electricity to specific bulbs. They then propose and test strategies for using parallel circuits and switches to increase the number of bulbs on a circuit. Finally, they are introduced to circuit diagrams. |
- Parallel circuits
- Switches
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Activity Six: Cold Shower
Electricity used by water heaters is the focus of this activity, which also reinforces concepts of energy transfer. Students investigate the amount of energy in joules needed to raise the temperature of water, then calculate the efficiency of different water heaters. They also consider alternate solutions to the expectation for hot water in a home. |
- Energy conservation
- Power
- Watts, joules
- Specific heat
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Activity Seven: Pay Up
Students compare different electric bills as they continue to explore concepts related to power consumption, efficiency of electrical appliances, and relative costs and benefits of specific electrical appliances. This activity also serves to review concept units used to communicate about energy transformation. |
- Energy conservation
- Energy flow and power
- Electrical efficiency
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Activity Eight: More for Your Money
Students conduct an experiment in which they determine and compare the power consumed and the efficiency of three systems that could be used to heat water. They apply data collected to confirm their response to the challenge in which they recommend appliances for the universal home. |
- Heat Energy
- Electrical Energy
- Energy Flow and Power
- Electrical Efficiency
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