MARKING GUIDELINE NATIONAL CERTIFICATE (VOCATIONAL) NOVEMBER EXAMINATION. PRINCIPLES OF COMPUTER PROGRAMMING (First Paper) NQF LEVEL 3

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1 MARKING GUIDELINE NATIONAL CERTIFICATE (VOCATIONAL) NOVEMBER EXAMINATION (First Paper) NQF LEVEL 3 20 NOVEMBER 2014 This marking guideline consists of 7 pages.

2 MARKING GUIDELINE -2- NC2370(E)(N20)V SECTION A QUESTION True 1.2 False 1.3 False 1.4 False 1.5 False 1.6 True 1.7 True 1.8 False 1.9 False 1.10 True 1.11 True False 1.12 False True 1.14 True 1.15 False (15 1) [15] QUESTION Many 2.2 Sequential 2.3 Write 2.4 Bubble 2.5 Separate 2.6 Radio buttons OR checkboxes

3 MARKING GUIDELINE -3- NC2370(E)(N20)V 2.7 Left 2.8 Address 2.9 Element 2.10 Function (10 x 1) [10] TOTAL SECTION A: 25 SECTION B QUESTION = (1 2 3 ) + (0 x 2 2 ) + (1 2 1 ) + (1 2 ) = OR =11 = 11 (3) 3.2 Write the number with leading zero's to make up the 8 binary bits: Flip the 1s and 0s: Add 1 to the least significant digit: Add the two's complement number to the first number, 101: (4) OR any number of bits 3 or more example: ) A function must always return a value, when executed A function must perform a specific task A procedure may return or not return a value It is independent of any object or event (Any TWO or any other applicable answer) (2) 3.4 By value By reference (2) It is a computer program made up of a group of individual units, or objects, as opposed to a traditional view in which programming is a list of instructions to the computer. Each unit is capable of getting messages, processing data and sending messages to other units/objects (Or any other applicable answer) (3)

4 MARKING GUIDELINE -4- NC2370(E)(N20)V QUESTION It is a collection of objects of similar type. Once a class is defined, any number of objects can be created which belong to that class. A class can also be seen as a template that commands what objects can and cannot do. It's a blueprint of an object. (Or any other applicable answer) (3) [17] 4.1 Dim intnumber(99) as Integer (The student may assign any name to the array) (2) 4.2 One-dimensional array (1) Two or more arrays that are separately defined, but are logically linked to each other. An operation on one of the arrays usually means that the other arrays are affected as well A specification of a set of data, and set of operations that can be performed on the data. The data type is referred to as abstract because the definition and operations are not dependent on how the data type has been implemented. 4.4 Array An array is a form of temporary storage. An array stores its data in memory. An array uses an index number to identify a particular item. Database A database is a form of permanent storage. A database stores its data in files. A database uses a primary key to identify a particular item in a table. (Any 1 2) (2) 4.5 A database: Can store larger amounts of data than any other data structure Stores the data permanently Allows the data to be shared across different applications Contains a database management system that controls the functioning and operations of the database Allows flexibility of how the data is stored Avoids duplication of data Allows data to be normalised (Any 3 1 OR any applicable answer) (3)

5 MARKING GUIDELINE -5- NC2370(E)(N20)V 4.6 Selection: Allows the program to make a decision or a range of decisions Iteration: Allows segments of code to be repeated OR any applicable answer (2) To round decimal numbers to a given number of digits (2) Syntax error OR only functions uses return (1) Sub procedures cannot return values (2) [19] QUESTION A signed integer is represented by a fixed number of bits in memory The most significant bit (MSB) is 1 for a negative number (Any TWO) (2) 5.2 Value will be converted to data type character (2) 5.3 It is the relationship that exists between normalised tables in a database (2) 5.4 To ensure the database is normalised. Allows the DBMS to extract data from different tables using joins (2) 5.5 Most database software does not support many to many relationships Many to many relationships cannot be represented in a relational schema. (2) It lets the user specify whether the results should be displayed in ascending or descending order. (2) It lets the user group a large set of results by the values in one or more of the fields. (2) 5.7 It is data files or database tables used for storing important data, such as names and addresses. Master file control what can be entered into the other tables. This data will be used for queries and reports. (Any THREE or any other applicable answer) (3) [17] For the whole of Question 5, OR any applicable answer

6 MARKING GUIDELINE -6- NC2370(E)(N20)V QUESTION It produces a message while the program is running It stops the program It may cause ' index out of range' or 'division by zero' error It may cause the program to enter an infinite loop The program will ''hang'/'crash'/stop responding to input (Any THREE) (3) 6.2 A debugger is a program that allows you to execute your program under its control. The programmer could give interactive commands to instruct how the program should run. The programmer could step through the code one line at a time, and look at variables. The programmer could set breakpoints and then let the code run at full speed. When the program reaches the breakpoint, it stops there and the programmer is in control again. A breakpoint is a place in the code where you want the debugger to stop. Some debuggers allow you to set conditional breakpoints, where the debugger will stop only if some condition is true. (Any THREE or any other applicable answer) (3) It is the code that checks data and then rejects it if it is invalid /'bad' (2) A log file is used to record messages from a running program To 'log' a message means to write it to a log file (2) It is an unexpected condition in the code that must be dealt with first, otherwise it will cause the program to stop Are caused by a calculation result that is too large for the variable it is assigned to 6.4 Using data validation Using of masking Disabling of buttons and controls that shouldn't be used Asking for user confirmation before doing anything that can't be undone (Any TWO or any other applicable answer) (2)

7 MARKING GUIDELINE -7- NC2370(E)(N20)V 6.5 Simplicity Consistency Feedback User control Understandable messages Screen display User help Use menus for navigation Use of status bar Choose most suitable controls Set the start-up position of the form on the screen Stick to a form style Don't change the screen layout too much Show hourglass when user should wait Disable/enable buttons as necessary Ask for confirmation for choices that cannot be undone Label screen objects clearly Provide screen tips (Any FOUR THREE (allocate 4 th mark if 3 correct) or any other applicable answer or example) (4) 6.6 It is about imagining how users might want to use the program What users might try to do Building the required defences into the program Try to make it difficult or impossible for problems to occur (Any TWO or any other applicable answer or example given) (2) [22] For the whole of Question 6, OR any applicable answer TOTAL SECTION B: 75 GRAND TOTAL: 100

NATIONAL CERTIFICATE (VOCATIONAL) ELECTRONIC CONTROL AND DIGITAL ELECTRONICS NQF LEVEL 2 SUPPLEMENTARY EXAMINATION 2010

NATIONAL CERTIFICATE (VOCATIONAL) ELECTRONIC CONTROL AND DIGITAL ELECTRONICS NQF LEVEL 2 SUPPLEMENTARY EXAMINATION 2010 (12041022) 19 February (Y-Paper) 13:00 16:00 Calculators may be used. This question