Physics 214 Chapter 5 Gotta Knows

What you Gotta Know in Chapter 5

0. How to make the light bulb light, using only a wire, a bulb, and a battery. ( Something that nearly half a harvard graduating class in electrical engineering could not figure out in less than three minutes (But most third graders can.)

1. What makes the electrons move down the wire.

2. Information about changing electric fields moves down the wire at the speed of light, but how fast do the electrons actually move down the wire and why.

3. What the definition of elctron current is, and what every single factor in the equation of i means and the ramifications thereof.

4. Why (itoem) what makes the long bulb light and why the round one doesn't. (This is another little item that lot's of the big guys and gals down at the big house don't understand much.) This is a biggie which you will learn more thoroughly in chapter six, only if you manage to grasp it at this level first.

5. How to hook up bulbs in series and parallel.

6. What effect adding more bulbs in series has on the brightness and why.

7. What effect adding more bulbs in parallel has on brightness and why.

(There are fine details in both 5 and 6 addressed in the text, which you can observe, and should make serious efforts to understand.

8. How to use the compass to determine direction and relative strength of current in a wire.

(The left hand rule on page 174 is ok, but you should really grasp the idea on page 190.)

9. What effect adding more batteries in series has on brightness and current.

10. What effect adding more batteries in parallel has on brightness and current.

11. Why the wire glows in the center but not down near the wire clips is actually a heat conduction concept, but one you should be able to understand fairly easily.

12. Make sure you understand all those goofy pictures on page 192 & 193. (Start by first putting the compass on top of the wire, then but the wire on top of the compass, using the same battery and bulb circuit.)