Computer studies analysis of questions and answers - ATIKA SCHOOL

Using one's complement, convert the decimal number -9 into 6-bit binary number.

3/1/2021

Using ones complement, convert the decimal number -9 into a 6-bit binary number.

(b) (i) State three standard coding schemes used in data representation.
(ii) In a certain coding scheme, each character occupies 7 bits. Letters of the alphabet are assigned consecutive codes. If letter N is represented by 1010010. What is the representation of letter A in this coding scheme?
(c) Using twos complement. show how the arithmetic below would be carried out on a 8-bit computer system.
(+54)- (+29)

Using one's complement, convert the decimal number -9 into 6-bit binary number.

(b) (i) State three standard coding schemes used in data representation. (ii) In a certain coding scheme, each character occupies 7 bits. Letters of the alphabet are assigned consecutive codes. If letter N is represented by 1010010. What is the representation of letter A in this coding scheme? (c) Using twos complement. show how the arithmetic below would be carried out on a 8-bit computer system. (+54)- (+29)

Explain how data in a computer system is secured using:

3/1/2021

Explain how data in a computer system is secured using:

(i) password;
(ii) user access level.
(b) State three characteristics of a suitable password.
(c) State two characteristics of a computer that is infected by computer viruses.
(d)(i) The figure below shows how data is transmitted through a public telephone line.

Name A, B, C and D.
(ii) State two advantages of using fibre optic cables over satellite in data communication.

(a) (i) Password

It’s a string of characters entered by a user to verify his or her identity.
The system compares the code against a stored list of authorized users. If the user is legitimate then the system allows the user access.

(ii) User level access

It’s a mechanism for limiting access to certain items of information or to certain control based on user identities and their membership in various predefined groups.

(b) Characteristics of a suitable password

Easy to remember
Should have appropriate length
Hard/difficult to guess

(c)

Slow or not booting.
Files not opening.
Functionality of some application failing.
Files or data getting lost.

(d) (i) Naming the parts

A — Sender/terminal
B — Digital waveform
C-Modem
D — Analogue waveform.

(ii) Advantages of fibre optic over satellite

Cost.
Supports broadband communication.
Signal is directed and therefore e secure.
It’s minimal to raise interference e.g. noise.

Using two examples, explain the term field properties as used in database design.

3/1/2021

Using two examples, explain the term field properties as used in database design.

(b) Below is an extract from a hospital database table.

(i) State with reasons the most suitable data types for the following fields:

(I) patient No;
(II) date registered;
(III) amount paid;
(IV) remarks.

(ii) Which would be the most appropriate primary key field for the above table?
(iii) What is the purpose of a primary key field in database design?
(iv) Describe how information about patients who registered after 09/08/06 can be extracted from the database.

(a)Field property:

Specifies details related to fields and table entries expected e.g. field size, format, decimal places etc.

(i)

(I) Patients No. - Data type - Text
Reasons — it combines both numeric and alphanumeric characters.
(II) Date -Date type -Date
Reason — Data type can be manipulated mathematically, e.g number of moths can be calculated between two dates.
(III) Amount paid — Data type - Currency/Numeric
Reason — it can be manipulated mathematically.
(IV) Remarks - Data type - Memo
Reasons — the content may be lengthy e.g. giving a paragraph.

The following are some of the phases in the systems development life cycle (SDLC): system analysis, system design, system implementation, system review and maintenance. State four activities that are carried out during the system implementation phase.

3/1/2021

The following are some of the phases in the systems development life cycle (SDLC): system analysis, system design, system implementation, system review and maintenance. State four activities that are carried out during the system implementation phase.

(b) Give three reasons why system maintenance phase is necessary in SDLC.
(c) State two instances where observation is not a viable method of gathering information during system analysis stage.
(d) Various considerations should be made during input design and output design.

State two considerations for each case.

Input design.
Onput design.

(e) State two reasons why an organisation may use other strategies of software acquisition other than developing their own.

RESPONSES

(a)(i) Activities (system implementation)

File conversion system change over.
Training, construction, installation.

(ii) System construction stage.

Coding
Module testing

(b)System maintenance stage is necessary

Correct the errors that may have escaped during the design.
To meet the changes in technology.
Changes in government policy. ‘
Changes in operating environment e.g. the system evolving (e.g . when a, newer version of software is released).

(c)Observation not viable method of gathering information:

Distance = when data is to be collected from a far place. if the people to be observed must be aware that they are being observed.
When the situation is risky for the observer.

(d)Input design:

Data capture method.
Input interface, between user and the system e.g. form.
Volume of input.
Frequency of input.
Output design
Form of output designed e.g. hard/soft copy.
Output layout.
Purpose of output.

(e)Other strategies other than system construction:

Constrained by time.
Constrained by cost
Constrained by human resource.
Legal requirements.

The following are some of the phases in the systems development life cycle (SDLC): system analysis, system design, system implementation, system review and maintenance. State four activities that are carried out during the system implementation phase.

The following are some of the phases in the systems development life cycle (SDLC): system analysis, system design, system implementation, system review and maintenance. State four activities that are carried out during the system implementation phase.

Machine language programs are more difficult to write than high-level language programs. State two reasons for this.

3/1/2021

Machine language programs are more difficult to write than high-level language programs. State two reasons for this.

(b) In order to process examination results of students in a school, their names, index numbers and scores in 11 subjects are required. The average score for each student is then determined and a grade assigned. This process is repeated for all 40 students in a class,
Draw a flowchart to:
. Read a student’s name, index number and the scores in all the subjects.
. Determine the student’s average score.
‘ Assign a grade to the student depending on the average score as follows:

Score Grade
80 ≤ score A
60 ≤score<8O B
40 ≤ score<60 C
score < 40 F

• Display the student’s name, index number, average score and the grade.
• Repeat the above steps for all the students in the class.
(e) Below ¡s a list of program segments in different generations of programming languages.
Identify the language for each.

(a) Disadvantages of machine level language It is time consuming to develop

It’s easy to make mistakes because only 0’s and 1 ‘s are used.
Program written for one computer model may not run on another computer model.

(b)

Start/Stop.
Computing average.
Assigning the grades.
Statement in the decision box.
Printing.
Looping (initializing, testing).

A firm operates an order system that coordinates orders, raw materials and inventory across its three factories. Currently the orders are processed manually at each factory and communicated to the others over the phone. The management intends to computer

3/1/2021

A firm operates an order system that coordinates orders, raw materials and inventory across its three factories. Currently the orders are processed manually at each factory and communicated to the others over the phone. The management intends to computerise their operations. State the first two computer professionals who will be required and their roles.

System analyst roles

Make an appraisal of the information needed of the firm in some area defined by management and specify the information which is required to meet the current and expected needs of the firm.

Programmer roles:

To advise the senior systems analyst on the feasibility and efficiency of the proposed program suit and when required to assist in it’s design.
To construct a new system based on the requirement as specified by the systems analyst.

Or
Network Engineer roles:

Responsible for planning designing and implementation of appropriate network between the three plans as specified by the systems analyst.

A firm operates an order system that coordinates orders, raw materials and inventory across its three factories. Currently the orders are processed manually at each factory and communicated to the others over the phone. The management intends to computerise their operations. State the first two computer professionals who will be required and their roles.

State three ways in which ICT can be used in shipping control.

3/1/2021

State three ways in which ICT can be used in shipping control.

Shipping control:
navigation.
loading and offloading.
docking
records management.
communication.

State three ways in which ICT can be used in shipping control.

Describe the following terms as used in mail merging: main document; and data source.

3/1/2021

Describe the following terms as used in mail merging: main document; and data source.

(a) main document;

Part of the document which appears in every mail document.

Purpose

Hold fields where information from the table is to appear.

(b) data source.

it’s a database/table

Purpose

Hold records which are to be merged to the main document.

Describe the following terms as used in mail merging: main document; and data source.

State two reasons why it is necessary to use standard furniture in a computer laboratory.

3/1/2021

State two reasons why it is necessary to use standard furniture in a computer laboratory.

Prevents people from straining. .
Table sizes allow all equipment to fit.
Optimization/utilization of room space.

State two reasons why it is necessary to use standard furniture in a computer laboratory.

Copyright laws are laws granting authors the exclusive privilege to produce, distribute, perform or display their creative works. It is a legal framework for protecting the works such as book publishing, motion-picture production and recording. State two

3/1/2021

Copyright laws are laws granting authors the exclusive privilege to produce, distribute, perform or display their creative works. It is a legal framework for protecting the works such as book publishing, motion-picture production and recording. State two challenges that are posed to these laws by ICT’.

Easy of communication .
Easy of duplication
Enforcing is still a problem e.g. officers are not computer literate.
Lack of capacity for people enforcing the law.

Copyright laws are laws granting authors the exclusive privilege to produce, distribute, perform or display their creative works. It is a legal framework for protecting the works such as book publishing, motion-picture production and recording. State two challenges that are posed to these laws by ICT’.

Explain why telecommuting is not suitable for a doctor when carrying out an operation on a patient.

3/1/2021

Explain why telecommuting is not suitable for a doctor when carrying out an operation on a patient.

Telecommuting:
Working form a remote place using a computer connected to the internet.
Screening patients requires direct interaction with the patients hence not the best.

Explain why telecommuting is not suitable for a doctor when carrying out an operation on a patient.

State the purpose of each of the following memories in a computer system. RAM and Hard disk

3/1/2021

State the purpose of each of the following memories in a computer system. RAM and Hard disk

(a) RAM
Holds data that is urgently need by the processor,
Random-access memory is a form of computer memory that can be read and changed in any order, typically used to store working data and machine code.
(b) Hard disk
Used to hold large volumes of data that is not urgently required by the processor — also for back up of OS and data.

State the purpose of each of the following memories in a computer system. RAM and Hard disk

Give two reasons why the use of finger prints and voice input can be used as reliable forms of security in computer systems.

3/1/2021

Give two reasons why the use of finger prints and voice input can be used as reliable forms of security in computer systems.

They cannot be:

faked
guessed
hacked
delegated.

Give two reasons why the use of finger prints and voice input can be used as reliable forms of security in computer systems.

Study the pseudocode below and determine its output.

3/1/2021

Study the pseudocode below and determine its output.

1. (a) T = O
(b) M = O
(c) K = I
2. (a) M M±T
(b) T = T+5
(c) K = K+1
3. Repeat step 2 while K < 3
4. Write M,T
5. Exit

Study the pseudocode below and determine its output.

The word race is appearing several times in a long story document composed using a DTP package. How would this word be safely replaced with the word content?.

3/1/2021

The word race is appearing several times in a long story document composed using a DTP package. How would this word be safely replaced with the word content?.

Invoke the search and replace command button.
Insert appropriate words in the find and replace fields on the dialog box.
Create a space before and after each word in the two fields

The word race is appearing several times in a long story document composed using a DTP package. How would this word be safely replaced with the word content?.

State four functions which are specific to Network Operating Systems.

3/1/2021

State four functions which are specific to Network Operating Systems.

Ensures that only authorized users access the network through logging in and out.
Restricts when and from where users can access the network.
Dictates which rules/protocols computers may use to communicate.
Supply application to users within a network.

State four functions which are specific to Network Operating Systems.

Distinguish between a formula and a function as used in spreadsheets.

3/1/2021

Distinguish between a formula and a function as used in spreadsheets.

Vertical Divider

Distinguish between a formula and a function as used in spreadsheets.

Formulae are user designed expressions that create a relationship between cells and return a value in a chosen cell. While a function is an inbuilt predefined (hidden sub-program) that is found in a spreadsheet program.

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

3/1/2021

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

Intranet is a company’s internal network to which outsiders cannot get access to while Internet allows outsiders to access company network if proper security measures are not implemented.

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

Define data communication.

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Define data communication.

Data communication -It is a term that describes the transmitting and receiving of data and/or signals data over communication links.

(b) State two characteristics of an effective data communication system.

Characteristics of an effective data communication system

Accurate
Secure
Timely

Define data communication.

List four activities carried out by a data processing system.

3/1/2021

List four activities carried out by a data processing system.

Input
Process
Control
Storage
Output

List four activities carried out by a data processing system.