FM radio waves

Which is higher in energy, FM radio waves with a frequency of 1.015 x 108 Hz (101.5 MHz) or visible green light with a frequency of 5 x 1014 Hz ... 

We are surrounded by electromagnetic waves at all times. Light, x-irradiation, TV, AM, and FM radio waves, ultraviolet, infrared, and microwaves are some of the common manifestations of these waves. All bodies in the universe, above absolute zero temperature, emit electromagnetic waves. The relationship of these waves is found in the electromagnetic spectrum (see Figure 12.1). All electromagnetic waves are characterized by their wavelength and frequency, and an... 

Arrange the following in order of decreasing wavelengths X-rays, ultraviolet light, FM radio waves, and microwaves. 

The electromagnetic radiation with the longest wavelength is FM radio waves, then miaowaves, followed by ultraviolet light, and then X-rays, which have the shortest wavelengths. 

Gamma rays X-rays Ultraviolet 0) (/) > Infrared Microwaves/radar Radio waves TV/FM AM... 

An FM radio station broadcasts at 99.5 MHz. Calculate the wavelength of the corresponding radio waves. 

Nonionizing radiation consists of parts of the electromagnetic spectrum that correspond to microwaves, also identified as RF waves and extremely low frequency (ELF) waves. RF waves range from 300 MHz to 30 GHz and correspond to AM radio, FM radio, TV, mobile telephone, and micro-wave oven transmissions. ELF waves are in the 50-60 Hz range and correspond to electrical transmission power line emissions. 

If a portable AM/FM radio receiver is available, place it about three feet from the inductor and battery. (If a small radio is not available, the inductor and battery can be taken outside, near an automobile radio.) Turn on the radio, set it for AM, and tune the frequency dial to a number where there are no nearby radio stations, so only a very low level of background noise is audible. Turn the volume up somewhat. Disconnect the neon tester, and then make repeated sparks with just the inductor and battery, as shown in Fig. 1.2, but using the primary coil (heavily insulated black wires). Loud clicks will be heard from the radio loudspeaker, each time a spark is made. The high voltage pulse generates a radio wave, which travels through the air to the radio antenna. (Further analysis of these various aspects of radio theory will be explained in later chapters.)... 

The longest wavelengths of light are radio waves, which are used to transmit the signals used by AM and FM radio, cellular telephones, television, and other forms of communication. 

Radio waves are a form of electromagnetic radiation with long wavelengths. Calculate the wavelength used to produce a frequency modulation (FM) radio signal that appears at 100.7 megahertz (MHz mega = 10 ) on the radio dial. 

An FM radio station broadcasts news at 98.0 MHz. What is the frequency of this radio wave in hertz ... 

The plasma frequency derived in Equation 24.60 also applies to electrons in the ionosphere. Radio waves below the plasma frequency (amplitude modulated [AM] and shortwave broadcast) are reflected back to earth by the ionosphere and can carry over long distances. Frequency modulated (FM) and TV frequencies ( 50 MHz) penetrate the ionosphere and reception is limited to line-of-sight distances. Spacecraft and direct broadcast... 

The free electrons in the ionosphere will reflect short wave radio waves at frequencies below their plasma frequency ( 50 MHz) but will transmit FM and TV frequencies. Spacecraft reentry creates a plasma whose frequency is much higher than that of the atmosphere, which accounts for the communication blackout during this phase of a space mission. 

AM radio waves (540-1600 KHz) as well as shortwave broadcasts (up to 20 MHz) can be heard over great distances because their waves are reflected back to Earth by the ionosphere. However, TV (Channel 2 is 55 MHz) and FM broadcasts (88-108 MHz) are limited to line of sight between the transmitter and receiver. With this information, what limits can you place on the electron density of the ionosphere ... 

PRACTICE EXAMPLE B An FM radio station broadcasts on a frequency of 91.5 megahertz (MHz). What is the wavelength of these radio waves in meters ... 

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