4021Q2 SPECIMEN COMPUTER SCIENCE

Extracted Content: 4021Q2 SPECIMEN COMPUTER SCIENCE

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Candidate Name Centre Number Candidate Number

ZIMBABWE SCHOOL EXAMINATIONS COUNCIL

General Certificate of Education Ordinary L evel

COMPUTER SCIENCE 4021/2

PAPER 2 Structured
SPECIMEN PAPER 2 hours 30 minutes
Candidates answer on the question paper.

No additional materials are required.

TIME 2 hours 30 minutes
INSTRUCTIONS TO CANDIDATES

Write your name, Centre number and candidate number in the spaces at the top of this page.

Answer all questions.

Write your answers in the spaces provided on the question paper.
INFORMATION FOR CANDIDATES

The number of marks is given in brackets [ ] at the end of each question or part question.

This specimen paper consists of 11 printed pages and 1 blank page.

Copyright: Zimbabwe School Examinations Council, Specimen Paper.

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A school stores a large amount of data. This include student attendance, For qualification and contact details. The school’s software uses a file-based Examiner's approach to store this data. The school is considering changing toa DBMS. Use

(a) State what DBMS stands for.

(b) Describe two ways in which the Database A dministrator (DBA) could
use the DBMS software to ensure the security of the student data.

(©) Describe how the school secretary could use a query processor.

[2]

(dq) TheDBMS has replaced software that used a file-based approach with a
relational database.
Describe how using a relational database has overcome the previous
problems associated with a file-based approach.

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2 Identify two differences between library functions and user-defined functions. For Examiner's Use

3 (a) _—_ Identify four components of the C.P.U and explain the purpose of each.

Component 1

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(b)

(a)

(b)

Identify any two features of GUI operating system.

1.

2

1.

2

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(a)

(b)

©

Convert 101101111, to hexadecimal.

Three digital sensors A, B and C are used to monitor a process. The
outputs from the sensors are used as the inputs to a logic circuit.
Signal X is output from the logic circuit.

Output X has a value of 1 if either of the following condition occurs:
e Sensor A outputs the value 1 OR Sensor B outputs the value 0.
e Sensor B outputs the valuel AND Sensor C outputs value 0.

Draw a logic gate to represent these conditions.

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A system developer designs software for a school. The software needs to be tested before it is delivered to the school.

(a) Explain software testing.

(b) State four levels of testing.
1.

2.

3.

4, [4]

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(a)

(b)

Explain the differences between

@ file server and client server

(ii) Routers and Bridges

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©

(a)

(b)

Give one function of a switch.

oe [4]
Explain the following constructs.
(i) iteration,
oe [2]
(ii) selection
oe [2]
Write an algorithm to sort an element using insertion sort.

[6]

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9 (a) Define a web browser. For

oo — 2
(b) State three facilities offered by a web browser.

Lo

2

3 [3]

10 (a) _ A nuclear reactor is cooled by pumping gas around the core. The
diagram below shows a reactor monitored and controlled by a
computer.

Nuclear power station

Hot gas
— outunder

CORE I

Cool gas
— inunder
pressuer

Write down any three reasons why a reactor is controlled by a computer.

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11

10

(ii) State any three sensors suitable for monitoring and controlling the
nuclear

1.

2

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