Download Chapter 9.1 Notes

9.1 Notes – Part 1
1. A changing electric field can produce a changing ____________________________________.
2. A changing magnetic field can produce a changing __________________________________.
3. The combination of these two fields is what produces an
______________________________________.
4. Changing current can produce changing electric and magnetic fields that move away from an antenna
at the speed of light and are called ______________________________________________.
5. The energy is contained in the electric and magnetic field or in the electromagnetic wave and this
energy is called ________________________________________________.
6. Electromagnetic waves travel at ________________________________ m/s through a vacuum.
7. 300,000,000 m/s is the same speed as the _________________________________.
8. We use the letter _____ to represent the speed of an electromagnetic wave.
9. The speed in the air is approximately the same as the speed in a ____________________.
10. All electromagnetic waves travel at the same speed, but they can have different
_____________________________ and ________________________________.
11. Equation for wavelength and frequency = _____________________________________.
12. c = _________
13. If our frequency is 1200 H, what is the wavelength?
14. The ____________________________ of a wave is the distance between peak of the electric field or
magnetic field in the wave.
15. The __________________ is the rate at which peaks pass a stationary point.
16. Wavelengths of electromagnetic waves range from millions of meters to as short as
__________________________________________.
17. The range of wavelengths and frequencies of electromagnetic waves is called the
_________________________________________________.
18. Video – What happens when we tune in a radio station?
19. Video – In what way do electromagnetic waves travel?
20. Video – What is the difficulty in using waves that are higher in the frequency?
21. The electromagnetic spectrum is divided into ________________, based on sizes of the wavelengths
of electromagnetic waves.
22. ____________________________ are the longest electromagnetic waves, some as long as several
thousand kilometers.
23. List the electromagnetic bands in order:
Longest
1
2
3
4
5
Shortest
6
24. Light is broken into 3 categories:
1.
2.
3.
Radio Waves
25. Radio waves are used to transmit radio and __________________________ signals.
26. Radio wavelengths can be less than ___ centimeter long or even ______________ of kilometers long.
27. At the radio or TV station, they have ________________________ that are used to convert sound
into electric signals which creates an electromagnetic wave.
28. These radio waves are than transmitted in all directions from an ________________________.
29. The waves travel to a receiving antenna and move at the _____________________________.
30. At the receiving antenna, there is another transducer that changes the electromagnetic wave back into
_________________________.
31. Each type of radio waves has a different _______________________. For example, waves from a
radio station are longer than waves emitted by your cell phone.
Microwaves
32. Microwave radiation has shorter wavelengths and higher _______________________ than radio
waves.
33. Microwave wavelengths range from approximately one millimeter (the thickness of a pencil lead) to
_______________________________ (about one foot).
34. Microwaves are used in __________________________________. They carry information from
point to point on the Earth, or from Earth to satellites.
35. Microwaves are also used in _______________________________ to detect and track moving
objects.
36. The ________________________ of the reflected wave can be measured to locate the object.
37. The reflected wave frequency is changed if the object is moving and this change can be measured and
used to determine the object’s ___________________.
38. In a _________________________________, the electromagnetic waves that are generated are tuned
to frequencies that can be absorbed by water molecules.
39. Video – What is the only part of the electromagnetic spectrum we can see?
40. Video – How do the police use the electromagnetic spectrum?
41. Video – What part of the electromagnetic spectrum to bees see flowers with?