Chapter 2 Understanding Functions and Operating 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 ?

• W is represented by the number code 87. 

2. Name and explain all supporting devices inside a CPU ?

• Control unite is to translate commands or instruction in a series and then continues them to the entire computer parts. This part is how the processor controls the entire computer operation.
• Arithmetic Logic Unit (ALU) is to process data by adding, Substracting, Comparing and using logical formulas.
• Memory is to collect or to store data to run an application program. The capibility on the memory capacity, which is stated in Byte,KByte.Mbyte and Gbyte unit.

3. What is the abbreviation and the function of ROM ?

• ROM (Read Only Memory) is a permanent memory that can be read but cannot be updated. ROM is to save computer operation program, such as BIOS and booting.

4. Name three examples of network interface cards ?

• ethernet
• arcnet
• token ring

5.Name and explain saveral  cables that use on a wired network ?

• UTP Cable (Unshielded Twisted Pair) it consists of a pair of plastic wrapped conducter and each is colored. The frequency ranges from 100 Hz to 5 MHz. A UTP connector is required to install a 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 similar 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 alike.

• coaxial cable consists of a main copper conductor with three wraps. the first and third are plastic wraps. the first and third conductor are isolator, while the second web in the 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 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 enable data transmission speed of Mbps-2 Gbps. moreover, the signal range is farther than any other cable types an as a wider bandwith. the optical fiber is fragile and therefore difficult to be moved and installed, needs an expensive maintenance, and the cost of the optcal fiber is relatively expensive.