http://www.ck12.org Chapter 5. Energy
FIGURE 5.154
What’s wrong with this picture? (Hint:
How does current get to the light bulb?)- Based on your answers to questions 1 and 2, write a simple equation to sum up the relationships among
current, voltage, and resistance.
Review
- What is resistance? Name the SI unit for resistance.
- Explain what causes resistance.
- Describe properties of a metal wire that would minimize its resistance to electric current.
- Extend the rugby analogy to explain why a longer wire has greater resistance to electric current.
- Copper wires have about one-third the resistance of tungsten wires. Why would copper be less suitable than
tungsten as a filament in an incandescent light bulb?