Chapter 9

Discovering Computers 2011 : Living in a Digital World Answers

True/False

1.  True
2.  False
3.  True
4.  False
5.  True
6.  True
7.  False
8.  True
9.  False
10. True
11. True

Multiple Choice

1. C
2. C
3. C
4. D
5. B
6. A
7. D
8. B

Matching

1.  E
2.  J
3.  H
4.  D
5.  F
6.  A
7.  G
8.  B
9.  C
10. I

Short Answer

1. Text messaging is a process where users sends and receives short text messages, typically fewer than 300 characters, on a phone or other mobile device or computer.

Mobile to Mobile: send a message from your mobile device to another mobile device. Mobile to E-Mail: send a message from your mobile device to an e-mail address anywhere in the world. Web to Mobile: send a message from a text messaging Web site to a mobile device, or request that a Web site alert a mobile device with messages of breaking news and other updates, such as sports scores, stock prices, and weather forecasts. Mobile to Provider: send a message by entering a common short code (CSC), which is a four- or five-digit number assigned to a specific content or wireless service provider, followed by the message, such as a vote for a television program contestant or an entry for a sweepstakes.

2. GPS satellites orbit Earth. Every thousandth of a second, each satelite sends a signal that indicates its current position to the GPS receiver. GPS receiver (such as in a car, a wearable device, a smart phone, a handheld device, or a collar) determines its location on Earth by analyzing at least 3 separate satellite signals from the 24 satellites in orbit.

Individuals use GPS technology by using smart phones or GPS receiver.

3. A local area network (LAN) is a network that connects computers and devices in a limited geographical area such as a home, school computer laboratory, office building, or closely positioned group of buildings. A metropolitan area network (MAN) is a high-speed network that connects local area networks in a metropolitan area such as a city or town and handles the bulk of communications activity across that region. 

A wide area network (WAN) is a network that covers a large geographic area (such as a city, country, or the world) using a communications channel that combines many types of media such as telephone lines, cables, and radio waves.

A wireless LAN (WLAN) is a LAN that uses no physical wires.

4. A network topology refers to the layout of the computers and devices in a communications network.

Five types of digital dedicated lines are ISDN lines, DSL, FTTP, T-carrier lines, and ATM.

5. Three types of digital modems are ISDN modems, DSL modems, and cable modems.

An ISDN modem sends digital data and information from a computer to an ISDN line and receives digital data and information from an ISDN line. A DSL modem sends digital data and information from a computer to a DSL line and receives digital data and information from a DSL line. A cable modem, sometimes called a broadband modem, is a digital modem that sends and receives digital data over the cable television (CATV) network.