1. UNIVERSITY OF NEBRASKA-LINCOLN 0 0 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 No. 0 0 No. Fill in this call number for our section: 6348

2. Class Averages (3 exams w/bonus points and homework quizzes) average 70.4 +95 90 - 85 +80 75 - 70 +65 60 - 55 +50 45 - 40 These cutoffs will not be raised…you can use them to determine your guaranteed lowest grade. 35 40 45 50 55 60 65 70 75 80 85 90 95 100

3. + - The switch is closed on this simple circuit of an electromagnet: time  What might affect how rapidly current reaches its maximum value? I = V/R time switch is closed

4. Leyden, Holland (1746) Petrus van Musschenbroek

5. The Leyden Jar capacitor - +

6. The act of discharging through an inductor creates a short-lived electromagnet. But rather than vanishing immediately the strength of the electromagnet fades slowly as an induced voltage tries to sustain the current a little longer! Discharging through an inductor should slow the process down: Remember the inductor slows down both turn-on and the turn-off.

7. Fully charged capacitor Current starts to flow + + – – + – I I I I I Maximum current Maximum positive current

8. Capacitor fully charged Current flows ( opposite direction !) + + – – I + – I + – I Current begins to die down I I

9. Oscillators Fully charged capacitor Energy: all E + + – – Capacitor charged Energy: all E Current starts to flow Energy: some E, some B Maximum current Energy: all B Current begins to die down  induced    C charges in opposite direction Energy: some E, some B Current flows ( opposite direction !) Energy: some E, some B + + – – + – II I I + – + –

10. “Oscillator” Transmitting antenna The “tank circuit” the text talks about

11. tunable oscillator Receiving antenna to speakers “variable capacitor”

12. variable capacitor induction coil

13. Frequency  A single loop: A small surface area capacitor size of inductor size of capacitor 1 A specially shaped metal “C”: small inductance coil tiny capacitor 2.45 GHz ++++ - - - -- - - -

14. A microwave’s MAGNETRON - -

15.       Recall: the water molecule is slightly “polar” it has “sides” that are oppositely charged

17. + - + - -- tungsten heating filament accelerated electrons slam into the “anode”

18. + - + - -- In which direction are the generated x-rays most likely to be traveling?

20. UNIVERSITY OF NEBRASKA-LINCOLN 0 0 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 No. 0 0 No. Fill in this call number for our section: 6348