Computer studies analysis of questions and answers

List three advantages and three disadvantages of fibre optic cable and Name two types of coaxial cables

17/11/2021

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(a) List three advantages and three disadvantages of fibre optic cable (6mks)
Advantages

immune to electro magnetic interference and ear dropping
fast and supports high band width
large distance can be covered because it has low attenuation
can be used in hazardous environment
smaller and lighter than copper

Disadvantages

connecting devices are expensive
installation is difficult
complex to configure
expensive/ difficult to repair

(b) Describe the following signals and state where each is applied in network communication. (4mks)
Analog

made up of continuous varied wave form.
it is transmitted over telephone line.
a codec converts an analog signal to digital for transmission via a digital medium

Digital

made up of non continuous discrete wave form computers
a modem converts a digital signal to analog for transmission over the analog media

(c) Name two types of coaxial cables (2mks)

thin net
thick net

(d) (i) Distinguish between microwave and satellite transmissions. (2mks)

Microwave transmission consists of point to point transmissions meaning a signal is divided through a focused beam from transmitter to receiver while satellite is usually launched into speck

(ii) Give an example of internet protocol (1mk)

ICPIP [Internet Control Message Protocol]
TCP [Transmission Control Protocol]
IP [Internet Protocol]

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State the function of each of the following

15/11/2021

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State the function of each of the following

(a) Network Interface Card (1mk)

A device that creates a physical link to the computer and the transmission media

(b) Modem (1mk)

modem converts a signal from digital to analog form for the purpose of transmission over the transmission media

(c) Repeaters (1mk)

receives a signal from one section of a network, clean it to remove any distortion, boosts/amplifies it and sends it to another section

Modem

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Distinguish between a microwave transmission and a radio transmission.

15/1/2021

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Distinguish between a microwave transmission and a radio transmission.

(b) Figure 1 shows a computer, network topology. Use it to answer the questions that follow.

(i)Identify the type of topology.
(ii) State the function of each of the parts labelled A and B.
(c) A computer laboratory experiences power supply problems. Describe three power related problems that should be addressed.

RESPONSES

b) (i) Bus topology
(ii) A - The Bus cable

It is a core section of the bus topology network which has all the nodes connected to it and data pass through it.

B — Terminator

It destroys data that does not reach its destination so that it doesn’t cause echo back.

c) Problems related to power that should be addressed

Blackout: This is unexpected discontinuation of power supply in the laboratory.
Power sage: Sudden drop of voltage levels that lasts less than a second.
Transients! surge: High voltage flowing.
Brownout: Partial blackout where there’s low voltage flow.
Short circuit: live wires touching each other’s
Loose connection, which may cause tripping or total power failure

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A school intends to install wireless media in their communication system. State three advantages of this mode of communication media.

15/1/2021

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A school intends to install wireless media in their communication system. State three advantages of this mode of communication media.

The school will find it easy to add or remove modes on the system.
Incase of new building is put up, there will be no need of interfering with the communication media.
Users will find it safer to move around as there are no wires around the rooms.
Students will be able to roam as they access the network.

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Explain three ways in which an operating system provides data security in a computer system

14/1/2021

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Explain three ways in which an operating system provides data security in a computer system

Access control:

Deals with the problem of verifying /authenticating the identity of a user before permitting access to the request resource (e.g. use of passwords, user account);

Encryption

Transforming data into an unreadable format so that they are safely transmitted;

Firewalls

Filters out unwanted data and programs/criminals/hackers/malicoius persons;

Log files

A means by which transactions in a computer system can be recorded thereby detering potential infiltrators;
Alerts
Alerting a user when he/she is about to delete a file/folder.

(b)State two instances where observation is not a viable method of gathering data during system analysis stage.

When the analyst wants to collect confidential information,
When there is a large group of people involved in the system,
Where the people you want to gather information from are vastly dispersed

A device used to re-construct data signal during data transmission to its original strength/amplify/boost/regenerate.

II. router.

It is a device used to facilitate movement of data or packets between two or more LANS of different configuration (expansion of networks).
Delivers a packet/data directly to destination computers.
Interconnects different networks/provides network services.

(ii) The figure below shows a network based on the bus topology.

(b)State two instances where observation is not a viable method of gathering data during system analysis stage. When the analyst wants to collect confidential information, When there is a large group of people involved in the system, Where the people you want to gather information from are vastly dispersed (c) (i) State the role of each of the following data communication devices: I. repeater A device used to re-construct data signal during data transmission to its original strength/amplify/boost/regenerate. II. router. It is a device used to facilitate movement of data or packets between two or more LANS of different configuration (expansion of networks). Delivers a packet/data directly to destination computers. Interconnects different networks/provides network services. (ii) The figure below shows a network based on the bus topology.

I. Identify the component labelled P.

The component P is the terminator.

II. State the function of the component labelled P.

Terminator in a backbone is used to prevent data signal from bouncing back/absorb signals.

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Explain why an intranet is a more secure way to share files within an organisation compared to the Internet.

12/1/2021

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Explain why an intranet is a more secure way to share files within an organisation compared to the Internet.

Intranet involves interconnection of computers within an organisation, in intranet it's easier to monitor the access and sharing of files since the users working in the organisation can be assigned accounts and passwords which will enable them access the files they are authorised to access unlike the internet where many people can access whatever is stored in the organisation website.

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Explain two ways in which the use of internet could make reporting of corruption easier

10/1/2021

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Explain two ways in which the use of internet could make reporting of corruption easier

(b) Explain two circumstances under which the use of wireless communication would be preferred in data communication.
(c) Figure 2 is an extract of a spreadsheet showing what the students had targeted to score and the actual score in a computer remedial class.

A performance factor is obtained by subtracting the target score from the actual score and dividing the difference by the target score.
Write a formula that uses cell references only that would be entered in cell:
(i) D2 to compute the performance factor.
(ii) E2 to display the statement ‘more remedials’ if the performance factor is less than zero, ‘exempted’ if the factor is greater than zero and ‘optional remedials’ if otherwise.
(iii) D8 to display the best performance factor.

RESPONSES

(a) Ways ¡n which internet makes reporting of corruption easier.

Interactiveness: the internet based technology enables real-time dialogue hence instantaneous reporting of cases;
Outreach: the technology allows the coverage of wide areas/can be reported from anywhere;
Social mobilisation: It is easy to use technology to create a network with people or organisations with similar concerns;
Anonymity: With use of the technology, it has become easy to report corruption cases without being known;
Security: The message sent reaches the destination with less risk of being intruded.

(b) Circumstances when wireless is preferred

When the targetted recipients are many and diverse e.g. different platforms, devices, geographical locations.
When the sender or receiver is mobile and it in practical to use wired media.
When there is no space or it is inconvenient to lay cables e.g in a congested town.
When the distance of travel is very big e.g extraterestial communication.

A performance factor is obtained by subtracting the target score from the actual score and dividing the difference by the target score. Write a formula that uses cell references only that would be entered in cell: (i) D2 to compute the performance factor. (ii) E2 to display the statement ‘more remedials’ if the performance factor is less than zero, ‘exempted’ if the factor is greater than zero and ‘optional remedials’ if otherwise. (iii) D8 to display the best performance factor.

Use of the 1F function
First selection & output
Second selection & output
Last selection & output

(iii) = Max (D2:D7)

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State three functions of networking operating systems other than providing network security.

10/1/2021

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State three functions of networking operating systems other than providing network security.

(b) Explain three ways in which an operating system provides data security in a computer system.
(c) Explain three circumstances under which observation method may be preferred during data collection.

(a) Functions of network operating systems

Provide access to network resources;
Supporting network services like protocols;
Support communication;
Respond to requests from applications;

(b) Ways in which an operating system provides data security

Access control: Deals with the problem of verifying /authenticating the identity of a user before permitting access to the request resource (e.g. use of passwords, user account);
Encryption - Transforming data into an unreadable format so that they are safely transmitted;
Firewalls - Filters out unwanted data and programs/criminals/hackers/malicious persons;
Log files - A means by which transactions in a computer system can be recorded thereby deterring potential infiltrators;
Alerts - Alerting a user when he/she is about to delete a file/folder.

(c)Preference of observation during data collection

When the subjects that are being observed need not be made aware of the fact;
When there is need to directly see what subjects do rather than rely on what they tell you;
When there is need to collect data without interfering with the working of the subjects;
When nature of data can only be collected via observation e.g. traffic flow;
When collecting data in situation that subjects may be unwilling to give information.

(b) Explain three ways in which an operating system provides data security in a computer system. (c) Explain three circumstances under which observation method may be preferred during data collection.

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State the role of each of the following data communication devices: repeater and router.

7/1/2021

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State the role of each of the following data communication devices:repeater and router

(b) Figure 3 shows a network based on the bus topology.
(i) Identify the component labelled P.
(ii) State the function of the component labelled P.
(c) Students of Neema Secondary School formed an environmental club with a goal of taking part in environmental conservation activities. Outline three ways in which they can use the internet to achieve this goal.
(d) (i) A company has three branches A, B and C where A is the headquarter. The local area network (LAN) at A is directly connected to the LAN at B and directly to the LAN at C. Explain two benefits of having the LAN at B also directly connected to the LAN at C. (4 marks)
(ii) State three ways in which a company can protect its computer network from hackers.

(a) (i) Repeater

A device used to re-construct data signal during data transmission to its original strength/amplify/boost/regenerate.

(ii) Router

It is a device used to facilitate movement of data or packets between two or more LANS of different configuration (expansion of networks).
Delivers a packet/data directly to destination computers.
Interconnects different networks/provide s network service s.

(b) (i) The component P is the terminator.
(ii) Terminator in a backbone is used to prevent data signal from bouncing back/absorb signals.
(c) Use of internet in environmental conservation club

Source of knowledge on environmental matters;
Collaboration with peers from other schools or organisations;
Dissemination of information on what the club is doing;
Seeking for funding from sponsors.

(d) (i) Benefits of linking branch B and C

Speed of communication between B and C is increased since the traffic between the two branches can be re-routed through the link BC;
If either AC or AB is down, the three branches can still communicate;
If the HQ systems fail, the two branches B and C can communicate using this link.

(ii) Ways to protect company network from hackers

Changing password frequently
Use of encryption;
Use of data proxies;
Use of firewalls to filter unwanted packets;
User restriction e.g. passwords/biometrics.
Use of complex password.

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State three hardware devices that may be required to connect a computer to an existing local area network.

7/1/2021

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A) State three hardware devices that may be required to connect a computer to an existing local area network. (3 marks)

A network adapter/network interface card
Network medium/cable
RJ45 connectors/BNC/ST connector/SC connectors/Fibre local connector
Data points (sockets to plug in the cable)
Switch/Hub
Access point/TP link

B) A publisher intends to use a desktop publishing programme to create a publication which is to have many graphics. State three ways in which the graphics may be acquired for this purpose. (3 marks)

Using digital camera
Scanning the graphics from other sources
Downloading from the internet
Drawing from scratch/Drawing tools
Clip art
Another file

C) Interpret each of the following spreadsheet formula:

(i) = countif(D2:D9, “>“&B4) (2 marks)

(ii) sumif(B3 :B 11, “4M”, D3 :D11) (2 marks)

(i) = Countif (D2 : D9, “>“ & B4)

Count those value in the range D2 :D9 with values greater than the value in cell B4).

(ii) = Sumif (B3 : B11, “4M” D3 : D11)

Sum the values in the cell range D3 : D11 for records whose
corresponding values in cell range B3 : B11 equals to “4M”

(D) The following are the fields of products table in a database created to store records of products manufactured in a factory:

product number
product name
price
product description

I. State the appropriate data type for each field. (2 marks)
II. State three properties to be put in place during table design to ensure integrity of the data entered. (3 marks)

I) Product Number — Number/Autonumber/Text

Product Name — Text/string
Price — Currency/Number
Product Description — Memo/Text/String

(II) Properties that can be set in the table design

Data type
Validation/Validation rule
Input mask
Setting required/null value status
Field size
Caption

(D) The following are the fields of products table in a database created to store records of products manufactured in a factory:

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State four outcomes that may result from using incorrect requirement specifications during systems development.

7/1/2021

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A) State four outcomes that may result from using incorrect requirement specifications during systems development. (4 marks)

The system will be delivered later than schedule
The system will not meet the user’s expectation
The cost of maintaining and enhancing the system may be excessively high.
The system may be unreliable and prone to errors and downtime.
The system will not meet legal requirements.

B) A school opted to use direct change over approach when installing a new system.
Explain three challenges that the school may face as a result of this approach. (6 marks)

If something went wrong in the new system, there will be no fall back has the business has to stall till the problem is sorted.
There will be a period of time where no system is available because the old one is switched off and the new one is being switched on.
There will be a period of upheaval while the system is brand new and the school staff are finding their way around it.
There is a possibility of sabotage by staff since there is no time to monitor and manage resistance to the new system.

C) State three reasons that may lead an organization to install an intranet. (3 marks)

Used to isolate the organizational resources from the internet/security.
Used to provide communication and collaboration among individual within the control.
Used to publish and share valuable information among the users easily, inexpensively and effectively via portals and intranet website/resource sharing.
Used to run critical applications that support business decision making.
Distributed processing facilities.
Cost Effectiveness.
Protects signal distortion.
Protects signal inteferance.

D) The figure below shows a coaxial cable. State the function of the part labelled A. (2 marks)

Used for blocking electromagnetic fields from entering the cable and producing noise.
Provides insulation.

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The topology below ¡s formed by combining two types of topologies.

6/1/2021

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The topology below is formed by combining two types of topologies.

The topology below ¡s formed by combining two types of topologies.

(a) Give one name for the combined topology in figure 2.

Hybrid topology/tree/hierarchical

(b) Name the two topologies forming the combined topology in figure 2.

Star and Bus topologies (line/linear)

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State three techniques used by a network administrator to detect and prevent computer crimes.

5/1/2021

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State three techniques used by a network administrator to detect and prevent computer crimes.

(b) A company in town wishes to link its offices together. The linking may be through wireless or fibre optic network media.
(i) State two benefits that the company would gain from the use of metropolitan area network (MAN).
(ii) State three advantages of using wireless over fibre optic network media.
(iii) State two limitations of wireless communication.
(iv) State two transmission media used in wireless transmission.
(c) State three ways in which computer virus infection can be prevented other than through restricting the usage of removable storage media.

RESPONSES

(a) Audit trail

Use of antimalware software
Data encryption
Log files
Firewall
Intruder detection
User access levels
Password/Biometrics

(b)(i) High speed communication

Reduce data transfer charges
Provides a secured network .
Allow remote access
Media cannot be vandalised easily

(ii) No cumbersome cabling needed between sites.

Support multi-channel transmissions.
Wireless supports un-directed signals therefore allowing many recipients.
Do not require access rights on the land between the buildings.

(iii)Line of sight requirement.

Expensive towers required/high initial cost.
Subject to interference such as passing radio waves and weather conditions.
Very difficult to restrict access if it is un-directed.
Hard to secure
Easy to hack

(iv) Satellite

Microwave
Radio waves/blue-tooth/infrared

(e) Firewalls

Antivirus
Policy formulation on the usage of internet/password/security
Using email instead of storage devices to transfer document files.
Use genuine/authentic/unpirated software

State three techniques used by a network administrator to detect and prevent computer crimes.

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The figure shows a network design. Use it to answer the questions that follow

4/1/2021

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(a) The figure shows a network design. Use it to answer the questions that follow.

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Explain the term search engine as used in the Internet

4/1/2021

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(a) (1) Explain the term search engine as used in the Internet. (2 marks)

(i) Search-engine
It is a web-based application used to locate for an item or information from world wide web.

(ii) Peter intends to download a movie from the Internet. State the three factors that may determine the total time taken to complete the download. (3 marks)

Factors that affects duration of download

The size of the video
The band width of the media used
Availability of network
Other activities that may be running in the computer.
Other restrictions enforced in the computer
The restrictions by the ISP
Speed of computer

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(a) List three advantages and three disadvantages of fibre optic cable (6mks) Advantages

​Disadvantages

​(b) Describe the following signals and state where each is applied in network communication. (4mks) Analog

​Digital

​(c) Name two types of coaxial cables (2mks)

(d) (i) Distinguish between microwave and satellite transmissions. (2mks)

​(ii) Give an example of internet protocol (1mk)

​State the function of each of the following

(a) Network Interface Card (1mk)

(b) Modem (1mk)

(c) Repeaters (1mk)

Distinguish between a microwave transmission and a radio transmission.

A school intends to install wireless media in their communication system. State three advantages of this mode of communication media.

Explain three ways in which an operating system provides data security in a computer system

Explain why an intranet is a more secure way to share files within an organisation compared to the Internet.

Explain two ways in which the use of internet could make reporting of corruption easier

State three functions of networking operating systems other than providing network security.

State the role of each of the following data communication devices:repeater and router

​A) State three hardware devices that may be required to connect a computer to an existing local area network. (3 marks)

​B) A publisher intends to use a desktop publishing programme to create a publication which is to have many graphics. State three ways in which the graphics may be acquired for this purpose. (3 marks)

​C) Interpret each of the following spreadsheet formula:

​(D) The following are the fields of products table in a database created to store records of products manufactured in a factory:

​A) State four outcomes that may result from using incorrect requirement specifications during systems development. (4 marks)

B) A school opted to use direct change over approach when installing a new system.​ Explain three challenges that the school may face as a result of this approach. (6 marks)

​C) State three reasons that may lead an organization to install an intranet. (3 marks)

​D) The figure below shows a coaxial cable. State the function of the part labelled A. (2 marks)

The topology below is formed by combining two types of topologies.

(a) Give one name for the combined topology in figure 2.

(b) Name the two topologies forming the combined topology in figure 2.

State three techniques used by a network administrator to detect and prevent computer crimes.

RESPONSES

​(a) The figure shows a network design. Use it to answer the questions that follow.

​​(a) (1) Explain the term search engine as used in the Internet. (2 marks)

Categories

Archives

(a) List three advantages and three disadvantages of fibre optic cable (6mks)
Advantages

Disadvantages

(b) Describe the following signals and state where each is applied in network communication. (4mks)
Analog

Digital

(c) Name two types of coaxial cables (2mks)

(ii) Give an example of internet protocol (1mk)

State the function of each of the following

A) State three hardware devices that may be required to connect a computer to an existing local area network. (3 marks)

B) A publisher intends to use a desktop publishing programme to create a publication which is to have many graphics. State three ways in which the graphics may be acquired for this purpose. (3 marks)

C) Interpret each of the following spreadsheet formula:

(D) The following are the fields of products table in a database created to store records of products manufactured in a factory:

A) State four outcomes that may result from using incorrect requirement specifications during systems development. (4 marks)

B) A school opted to use direct change over approach when installing a new system.
Explain three challenges that the school may face as a result of this approach. (6 marks)

C) State three reasons that may lead an organization to install an intranet. (3 marks)

D) The figure below shows a coaxial cable. State the function of the part labelled A. (2 marks)

(a) The figure shows a network design. Use it to answer the questions that follow.

(a) (1) Explain the term search engine as used in the Internet. (2 marks)