3.1.1

5. unchecked, 0, not present
6. checked, one, present
7. reverses conditions for 5 and 6
9. 38 to 5000
11. 1718
12. 1655
14. switch red and black wires
15. electromagnet turns reed switch on
16. normally closed
18. light shining=closed photoresistor
19. the more light the more resistance in the phototransistor
20. reverse programming
21. leave alone

Conclusion:

1. It displays the concepts of normally open and normally closed because the lines touch for one side and don't for each other.

2. A computer is able to understand analog signals because it uses A/D converter.

3. The molecules move faster and so there is less resistance as something gets warmer.