1. How does the color of a heat resistor change when it warms up?

2. What kinds of light bulbs are used in your classroom?

3. What kinds of light bulbs are used in your home?

4. What produces the light in a LED lamp?

5. How does an incandescent light bulb work?

6. What are the disadvantages of halogen lamps?

7. Where are the following elements used: wolfram, nitrogen and argon?

8. Why cannot you see the light of an LED remote?