Electric Power
Learning Objectives
- Students will be able to calculate electrical power using multiple formulas
- Students will be able to understand energy consumption and electricity costs
- Students will be able to apply power concepts to real household devices
Core Concepts
- Power as energy per time
- Joule heating
- Energy efficiency
Formulas
$$P = VI$$
Power as voltage times current
$$P = I^2 R$$
Power dissipated in a resistor
$$P = \frac{V^2}{R}$$
Power in terms of voltage and resistance
$$E = Pt$$
Energy as power times time
Units
| Watt | W |
| Kilowatt-hour | kWh |
Interesting Fact
The resistance of a light bulb filament increases as it heats up, making the power calculation complex
Key Scientist
James Prescott Joule
Discovered that electrical energy is converted to heat in resistors (Joule heating)
Modern Research
Energy efficiency research explores ways to minimize power dissipation through quantum tunneling effects and superconductors.
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