Physical science chap. 12

16. Frequency 17. C 18. CRT 19. Moving electric field 20. Infrared waves 21. Radar 22. Microwaves 23. Carrier wave

16. Wavelength 17. Speed of light 18. Television 19. Moving magnetic field 20. TV remote control 21. Tracking storms 22. Cooking food 23. Frequency modulation

Radio waves enter a long, narrow tunnel. Radiation with wavelengths much larger than the width of the tunnel will be absorbed more than radiation with smaller wavelengths. Would you expect AM or FM car radios to fade out more when traveling through tunnels. Why?

AM, because they receive longer wavelengths than FM.

Certain chemical reactions can be made to take place by shining light on them. The energy carried by the light photons causes the reaction to occur. Which color of light, red, or blue, would be most likely to start the reaction? Why?

Blue light because it has higher frequencies and higher energy than red light.

Frequency of electromagnetic waves that a radio station is assigned

Carrier wave

Frequency of the electromagnetic wave that a radio station is assigned- _ _.

Carrier wave.

The image on a television screen is produced by a _ _ _.

Cathode-Ray tube

Television channels 2 through 6 have frequencies just below the FM band range, while channels 7 and above have mug higher frequencies. Which had a shorter carrier wave length, channel 3 or channel 8?

Channel 8 would have the shorter wavelength.

As the frequency of an electromagnetic wave decreases, it's energy _.

Decreases

Transverse waves that are produced by vibrating electric charged and consist of vibrating electric and magnetic fields are _ _.

EM waves

Waves produced by an oscillating electric charge

Electromagnetic waves

When the astronauts were working on the moon, mission control would ask a question, and there would be a delay before the astronauts answered. Why did this happen?

Even though radio waves travel at 3000,000 KM/S, the distance to the moon was so great it took time for the controller's question to get to the moon and then for the answer to get back.

What is the name of the ability of some materials to absorb ultraviolet light and remit it as visible light?

Fluorescence

What type of electromagnetic wave is the most energetic?

Gamma rays

System of satellites used to determine longitude, latitude, and altitude...

Global positioning system (GPS)

FM radio wave frequencies are _ _ AM waves.

Higher than

A remote control uses _ _ to communicate with a television set.

Infrared waves

Wave with wavelengths between radio and visible light

Infrared waves

What type of wave has wavelengths slightly longer than humans can see?

Infrared waves

What light would be more likely to cause a reaction to occur, a bright red light of a dim red light? Why?

It wouldn't matter. Intensity doesn't affect the energy of the photons.

Short radio waves..

Microwaves

Electromagnetic waves can behave like what type of particle?

Photons

Particles of radiant energy

Photons

Electromagnetic waves carry _ _.

Radiant energy

The kind of energy carried by electromagnetic waves- _ _.

Radiant energy

Cell phones use _ waves to transmit information.

Radio

Electromagnetic waves with the longest wavelengths

Radio waves

What type of wave has wavelengths greater than about 1 mm?

Radio waves

_ _ are the type of electromagnetic waves often used for communication.

Radio waves

Electromagnetic waves with the longest wavelength- _ _.

Radio waves.

What describes X-rays?

Short wavelength, high frequency

How does a radio signal go from a disc jockey speaking into a microphone at a radio station to your ear?

Sounds from disc jockeys mouth are changed into electric impulses in the microphone. They modify the carrier wave. It reached the metal antenna of a radio. The vibrating electrons produce a signal by the radio to vibrate the speaker of the radio. This then reaches to the ear.

How do police use infrared-sensitive goggle to follow criminals at night?

The body of the person trying to hide is warmer than the surroundings.

Many new cars have video screens that can display a map and tell the driver where she is and how to get to where she wants to go. How is this possible?

The car is hooked up to the Global Positioning System (GPS).

Device that can both transmit and receive a radio signal

Transceiver

What type of wave enables skin cells to produce vitamin D?

Ultraviolet waves

Electromagnetic frequencies to which our eyes are sensitive

Visible light

What changes in an AM radio wave?

Wavelengths

Waves used in medical imaging

X-rays

Ultra-high frequency electromagnetic waves between ultraviolet and gamma rays in frequency- _.

X-rays.