UNIVERSITY OF MALTA THE MATRICULATION CERTIFICATE EXAMINATION INTERMEDIATE LEVEL

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UNIVERSITY OF MALTA
THE MATRICULATION CERTIFICATE EXAMINATION
INTERMEDIATE LEVEL
COMPUTING
May 2011
MARKING SCHEME
MATRICULATION AND SECONDARY EDUCATION
CERTIFICATE EXAMINATIONS BOARD
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A1
a.
1 mark per correct line
A B
C D
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b. A Half-Adder.
A2
A3
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c.
Adds two bits received at A and B and produces the sum at C and the 1
carry at D.
a.
A+B using either a Karnaugh map or Boolean algebra (Distributive law, 4
Laws of Tautology, Laws of Absorption)
b. A
B
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a.
3
Three from:
• Batch – controls a job from beginning to end;
• Online – controls Internet-based applications;
• Multi-access – controls multiple users accessing same resource;
• Real time – controls the immediate processing of data.
b. Outline of the interaction of any one of the above. Eg. Batch – no 3
interaction whatsoever because all data that is required for processing is
available in system.
A4
a.
Components of CPU are the CU, ALU and Registers.
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3
b.
Main memory
Register
Register
Secondary storage
A5
a.
Sort practical example mainly involves the efficiency to search.
b. Insertion sort introduces an item at a time ensuring it’s correct place.
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Bubble sort compares neighbouring items and swaps them if necessary.
A6
A7
A8
a.
i. System and Application.
ii. System – controls how the computer works + suitable example.
Application – performs productive tasks + suitable example.
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a.
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A form of learning (education) through the use of computers
connected to the Internet.
ii. Advantage – Students move at their own pace or other relevant
advantage. Disadvantage – No tutor-student interaction or other
relevant disadvantage.
b. Example - WebCT, Moodle or other relevant example (1 mark) +
description (1 mark).
c. Remote access is the ability to get access to a computer or a network
from a remote distance.
i.
a.
a.
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2
1
i. -128 to 127
ii. -12 = 11110100
95 = 01011111
i. A law to protect personal information that needs to be processed
either manually or by a computer.
ii. Data protection commissioner – person who enforces the act.
Data controller – legal person who controls and is responsible for
the keeping and use of personal information.
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Internet – large network of networks i.e. connects millions of computers
together globally (the hardware infrastructure).
WWW – way of accessing the information over the Internet.
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b. URL – global address of some information on the WWW + example.
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c.
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1
A10 a.
i. Server – a computer system or program running a service/s.
ii. Proxy server – server that acts as an intermediary for requests
from clients seeking resources from other servers
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•
•
•
Improved data consistency and portability.
Control over data redundancy.
Greater security.
Less need of maintenance.
b. Flat - any database which exists in a single file in the form of rows and
columns, with no relationships.
Relational – database with tables linked together.
B1
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b. Data within the range + valid example
Data outside the range + valid example
Data at the boundaries of the range + valid example
b.
A9
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a.
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The SDLC gives the developer a methodical and sequential well-defined 2
set of well-tested and proven-to-work sequence of stepwise activities
and responsibilities that build on top of each other
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b
B2
Top-down approach – breaking down of a system to gain insight into its
compositional sub-systems.
Bottom-up approach – pieces together small systems to give rise to
grander systems, thus making the original systems sub-systems of the
emergent system.
Pseudo-code method – compact and informal high-level description of a
computer programming algorithm that uses the structural conventions
of a programming language, but is intended for human reading rather
than machine reading.
Flowchart method – is a type of diagram that represents an algorithm or
process, showing the steps as boxes of various kinds, and their order by
connecting these with arrows.
c. Three from:
• Reuse;
• Manageable;
• Maintainable;
• Defined responsibilities;
• Individual component testing;
• Ease to manage.
d Two stages before from: Domain research, requirements specification
and Functional analysis + purpose of each stage
Two stages after from: Implementation, testing and maintenance. +
purpose of each stage
a. LAN – office, school, etc.
MAN – city, large campus, etc.
WAN – country to country, etc
b.
i. Physical design of a network and how data is actually transferred
in a network.
ii. Bus:
Each computer or server is connected to the single bus
cable through some kind of connector.
Ring:
Set up in a circular way where data travels around the
ring in one direction and each device on the right acts as
a repeater to keep the signal strong as it travels.
Star:
Each network host is connected to a central hub.
Mesh: Whose nodes are all connected to each other.
iii. Bus:
If the network cable breaks, the entire network will be
down.
Ring:
The network is dependent on the ability of the signal to
travel around the ring.
Star: The central hub represents a single point of failure.
Mesh: Too costly and complex.
c.
i. A way of sub-dividing a communications system into smaller
parts called layers.
ii.
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•
Physical Layer: defines the electrical and physical
specifications for devices. Data unit: Bit.
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4
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Data Link Layer: provides the functional and procedural
means to transfer data between network entities and to
detect and possibly correct errors that may occur in the
Physical Layer. Data unit: Frame.
Network Layer: provides the functional and procedural
means of transferring variable length data sequences
from a source host on one network to a destination host
on a different network. Data unit: Packet.
Transport Layer: provides transparent transfer of data
between end users, providing reliable data transfer
services to the upper layers. Data unit: Segments.
Session Layer: controls the connections between
computers. Data unit: Data.
Presentation Layer: establishes context between
Application Layer entities, in which the higher-layer
entities may use different syntax and semantics if the
presentation service provides a mapping between them.
Data unit: Data.
Application Layer: interacts with software applications
that implement a communicating component. Data unit:
Data.
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