TRUE/FALSE QUESTIONS:

Quiz chapter 4TRUE/FALSE QUESTIONS:

1) The transmission media that are used to convey information can be classified as guided or unguided. _________2) Twisted pair may only be used to transmit analog transmissions. _________3) Coaxial cable is used to transmit both analog and digital signals. _________4) Guided media employ an antenna for transmitting through air, vacuum, or water.

_________5) The characteristics and quality of a data transmission are determined both by the characteristics of the medium and the characteristics of the signal. _________6) Twisted pair is much less susceptible to interference and crosstalk than coaxial cable. _________7) Microwave is used for satellite communications. _________8) Data rate and distance are not a key concern when designing a data transmission system. _________9) The most commonly used medium in the telephone network is twisted pair. _________10) Unshielded twisted pair provides better performance at higher data rates. _________11) Coaxial cable can be used over longer distances and support more stations on a shared line than twisted pair. _________12) Attenuation is significantly lower for optical fiber than for coaxial cable or twisted pair and is constant over a wide range. _________13) The same antenna cannot be used for both transmission and reception in two way communication. _________14) The parabolic reflective antenna is a type of antenna used in terrestrial microwave and satellite applications. _________15) Microwave is used in cellular systems. _________FILL IN THE BLANK QUESTIONS:

1) Twisted pair, coaxial cable, and optical fiber are examples of _________ media, which provide a physical path along which signals are propagated.

2) In a data transmission system the __________ medium is the physical path between transmitter and receiver.

3) Optical fiber transmits a signal encoded beam of light by means of __________ . This can occur in any transparent medium that has a higher index of refraction than the surrounding medium.

4) The least expensive and most widely used guided transmission medium for both analog and digital signals is _________ .

5) For __________ media the bandwidth of the signal produced by the transmitting antenna is more important than the medium in determining transmission characteristics.

6) A key difference between Category 3 and Category 5 cable is the number of _________ in the cable per unit distance.

7) A thin, flexible medium capable of guiding an optical ray is an _________ .

8) Often used in LANs, __________ transmission has a higher refractive index at the center which makes the light rays moving down the axis advance more slowly than those near the cladding.

9) Wireless transmission frequencies in the range of about 1 GHz to 40 GHz are referred to as __________ frequencies. Highly directional beams are possible at these frequencies.

10) Defined as an electrical conductor, or system of conductors, used either for radiating or collecting electromagnetic energy, unguided media uses an __________ to achieve transmission and reception.

11) The simplest radiation pattern is produced by the _________ antenna, which is a point in space that radiates power in all directions equally. The actual radiation pattern is a sphere with the antenna at the center.

12) A single orbiting satellite will operate on a number of frequency bands called __________ channels.

13) A form of attenuation known as _________ , is when a transmitted signal attenuates over distance because the signal is being spread over a larger and larger area.

14) The __________ frequency band is used for satellite communication, radar, terrestrial microwave links, and wireless local loop.

15) Used for amateur radio, CB radio, and international broadcasts such as BBC and Voice of America, __________ propagation is a signal from an earth based antenna reflected from the ionosphere back down to earth.