Chapter 2. Understanding Fuctions And Operations Of Various ICT Devices

A. Multiple Choice

1. A
2. C
3. B
4. B
5. E
6. E
7. C
8. B
9. A
10. C

B. ESSAY

1.  In ASCII code, by what code is letter W represented?
2. Name and explain all supporting devices inside a CPU!
3. What is the abbreviation and the function of ROM?
4. Name three examples of network interface cards!
5. Name and explain several cables that use on a wired network!

ANSWER!!!

1.  In ASCII code, the letter W is represented by the number code 87.
2.   - Control unit is to translate commands or intructions in a series and then continues theem to
           the entire computer parts.
       - Arithmetic Logic Unit (ALU) is to proces data by adding,subtracting,comparing,and using
          logical formal
       - Memory is to collect or to store data to run an application program.
3. ROM ( Read Only Memory ). And the function of ROM is to save computer operation program,such as BIOS and booting.
4. Ethernet, arcnet, and token ring.
5. UTP Cable ( Unshield Twisted Pair ),it consist of a pair of plastic wrapped conductor and each is colored. The frequency ranges from 100 Hz to 5 MHz. A UTP connector is required to install UTP cable on network card, such as RJ 45 connector. The cost of UTP is relatively cheap.

          STP Cable ( Shielded Twisted Pair ), STP cable is simillar with UTP cable, except that it has double     wrap. The middle wrap is a metal shield or metal foil to avoid electromagnetic interference. Other than that, STP cable connector and UTP cable connector are a like.


          Coaxial Cable, coaxial cable consists of main copper conductor with three wraps. The first and third are plastic wraps. The first and third conductor are isolator, while the second wrap in teh middle is a conductor. The connectors are BNC ( Bayonet Network Connector ), T-connector, and 50 ohm terminator. The terminator acts as a signal buffer in order not to obstruct the original signal.


       Optical Fiber, Optical fiber is made of plastic or glass  that acts as a medium for signal transmission in the form of light. Connector for the optical fiber is an FO connector. Optical fiber enabled data transmission spedd of 10 Mbps- 2 Gbps. Moreover, the signal range is farther than any other cable types and has a wider bandwith. The optical fiber is fragile and therefore difficult to be moved and isntalled, needs an expensive maintenance, and the cost of the optical fiber is relatively expensive.