Electrical Technology Digital Electronics Memo 1 (English)

November 2024 — Grade 12 / Matric — Electrical Technology

Memo 2024 Grade 12 English

↓ Download PDF 📄 469.1 KB View Exam Paper

Preparing document

📋 Document Analysis

🎯 200 marks 📄 6 pages 📝 72 items found 📚 3 topics

See full analysis

Questions — A Preview of What to Expect in the Document

This section provides a quick preview of questions from the document. It may not display every question or the complete wording of each one. For the full content, including diagrams, tables and other information, view the original PDF above.

2.4All calculations must show the formulae. Substitution of values must be done correctly. All answers MUST contain the correct unit to be considered. Alternative methods must be considered, provided that the correct

2.5Where an incorrect answer could be carried over to the next step, the first answer will be deemed incorrect. However, should the incorrect answer be carried over correctly, the marker has to re calculate the values, using the incorrect answ

Q1— Section header —

Q2— Section header —

2.1Workplace means any premises or pla ce where a person performs work in the course of employment. (2\

2.2Your right to fair labour practices. Your right to work reasonable hours. Your right to belong to a trade union. Your right to earn a living wage. Your right not to be dis criminated against. Your right to work in a safe environment.

2.3Poor ventilation reduces the correct amount of oxygen which might lead to drowsiness. NOTE: If reference is made to other effects that relates to poor ventilation like drowsin ess, accidents etc. the answer will be accepted on merit.

2.4To dismiss an employee without due process. To reduce the rate of remuneration without due process Alter the terms of conditions of his/her employment to terms of conditions that is less favourable to him/herself.

2.5Equipment may be damaged making it unsafe endangering the life of other users which might lead to an accident/injury. (2\ [10] Electrical Technology: Power Systems DBE/November 202410

Q3— Section header —

3.1.1Inductive reactance is the opposition to the flow of current when an inductor is connected to an ac supply Inductive reactance is the opposition offered to the flow of alternating current by an inductor.

3.1.2Bandwidth is the range of frequencies for whic h the circuit output voltage (or\ current value equals 70,7 % or more of its maximum amplitude. NOTE: A band of frequencies centred around the resonant frequency without mentioning 70,7% of the amplitude will be

3.2.1Lagging (1\

3.2.2(3\

3.2.3(3\

3.2.4(3\

3.2.5NOTE: Rotation and V are compulsory marks , thereafter any two correctly placed labels. and X

3.2A decrease in frequency caused the inductive reactance to decrease and the capacitive reactance to increase. When these two values move closer to one another their effects cancel each other out decreasing the im

3.3.1(3\

3.3.2(3\

3.3.3= I = 3,83 A = X

3.3.4= X (3\

3.3.5(3\ [35] Electrical Technology: Power Systems DBE/November 2024 NSC Ma rking Guidelines Copyright reserved35

Q4— Section header —

4.1The load can be balanced in a three phase system. Both single phase and three phase loads can be powered from a three

4.2.122 kV 50 Hz (2\

4.2.2Nuclear fuel Wind ater Solar (2\

4.2.3After generation the voltage is stepped u to a value between 220 kV to 765 kV. It is then transmitted over long distances by means of cables made of aluminium and steel to distribution stations where it is stepped down

4.3.1Star (1\ .3.2 OR NOTE: If a candidate give the correct sequence but in a different

4.4.1(3\

4.4.2OR (3\

4.4.3(3\

4.4.4(3\

4.4.5OR (3\ Electrical Technology: Power Systems DBE/November 2024 NSC Ma rking Guidelines Copyright reserved

4.5.1Synchronous motors. Phase advancers. (1\

4.5.2NOTE: Because the capacitors are not labelled in the prescribed textbook, an exception is made to the rule of labelling . 3 Marks will be awarded if the capacitors are correctly drawn without labels. (3\

4.5.3The two wattmeter method would be preferred because there is no neutral connection available, one can only connect between the lines. (2\

Q5— Section header —

5.1Transformers are used for raising or lowering the voltage in an AC circuit with a corresponding decrease or increase in cu rrent. (2\ 5. A transformer is an electrical device

5.3.2The laminated iron core reduces the circulating currents (eddy currents\inside the core material reducing the heat generated by them making the transformer more efficient. The laminations are designed to increase the efficiency of a

5.3.3The iron core in the core type transformer is almost entirely surrounded by windings where in the shell

5.3.4The iron core of a transformer is continuously subjected to magnetic polarity changes while switched on. Before the magnetic polarity can be reversed, the residual magnetism in the core has to be forced to zero.

5.4.3OR (3\ 5. .4 (3\ 5. Burn

Q6— Section header —

6.1Drill press Bench Grinder Lathe (2\

6.2.1There is a lower than required insulation resistance reading between coil V and earth the minimum required insulati on resistance between a coil and (1\

6.2.2When the motor is powered any person that touches any bare metal part of the motor may be electrocuted. Sparking may occur which might create a fire hazard. If the motor is powered with t he indicated fault, the motor can be

6.2.3(3\

6.3.2(3\

6.3(3\ OR

6.4.1MC N/ O is a retain /latching co ntact that will keep the contactors energised

6.4.2Contactor T is an ON delay timer that creates a time delay of 5 seconds before switching its contacts. (2\

6.4.3MC s connected in series with the normally closed contacts of the timer and MC This means that it will be energised as soon as the start button is pressed

6.4.4After 5 seconds the timer T will open i ts N/C contact de energising MC while closing its N/O contact and energising MC

6.5.1(3\

6.5.2(3\

6.5.3NOTE: If a candidate substitute the phase angle, voltage and current correct without showing the calculation of the phase angle, 3 marks will be awarded for the substitution step. OR NOTE: 3 marks a re allocated to the substitution step.

Q7— Section header —

7.1.1Input scan Output scan (2\

7.1.2After the PLC has executed the programme instruction, it processes each rung of the pro gramme in a line by line

7.2.1OR gate (1\

7.2.2NOTE: Mark the ladder diagram according to the answer in 7.2.1 (3\

7.2.3W = X = Y = 1 Z = 1 NOTE: Mark the truth table accor ding to the candidate

7.3.1screte /Digital Analogue

7.3.2Irrigation control Monitoring of rivers and dams Numerous chemical , petrol and diesel manufacturing by remote monitoring (2\

7.3.3An inductive proximity sensor is used to detect the presence of metal objects and whether they are ferrous or nonferrous. A capacitive proximity sensor uses an electrostatic field which can sense motion,

7.4NOTE: If a candidate closes the O/L or STOP inputs that were given, a mark will be deducted for each one that is closed, because the program will not operate correct according to the give n diagram in the question.

7.57.

5.1A = Three Phase AC supply B = AC to DC converter /Rectifier C = Filter (3\

7.5.2AC synchronous squirrel cage induction AC asynchronous wound rotor AC synchronous with a permanent magnet AC synchronous with brushes or brushless (2\

7.5.3The DC to AC inverter inverts the DC voltage back to an AC voltage. This is done by switching the IGBT s on and off at a high frequency.

7.5.4Pulse width modulation (PWM\is a modulation technique that generates variable width pulses to represent the amplitude of an analogue input signal. The output switching transistor is on

Topics Identified

CircuitsMachinesConstruction

Mark Allocation

Total200 marks

Sections15 + 10 + 35 + 35 + 30 + 35 + 40 = 200 marks

Paper information

SubjectElectrical Technology

Year2024

SessionNovember

TypeMemo

PaperPaper 1

LanguageEnglish

Pages16

Downloads6

Examination context

Decade2020s

Years ago2y

SeasonSpring (SH)

Start dayTuesday

Exam periodNovember 2024

Days since exam721

About Electrical Technology examination preparation

This Grade 12 examination resource can be used as part of a structured revision programme. Past papers are most useful when learners attempt questions independently, work within a realistic time limit, and review their answers afterwards.

How to use this resource for revision

A past examination paper is most useful when it is treated as an active revision exercise. Try the questions yourself before checking the corresponding memorandum. Where you make an error, identify the reason — was it a knowledge gap, a calculation mistake, an interpretation issue, or an examination technique problem?

For stronger examination practice, complete the paper without unnecessary interruptions and keep track of the questions that take the most time. Afterwards, review the memorandum and separate knowledge gaps from mistakes caused by interpretation, calculation, structure, or examination technique.

understanding question requirements

applying subject knowledge

working under time constraints

checking answers

identifying revision priorities

A practical revision approach

Start by completing the resource without looking at the memorandum. Review incorrect and incomplete answers afterwards and make a short revision list based on the areas that caused difficulty.

Grade 12 subject hubs

Each matric subject has its own dedicated hub on Freemode with every past paper and marking memorandum we have archived for that subject.

➗ Mathematics View papers → 📊 Mathematical Literacy View papers → ⚗️ Physical Sciences View papers → 🧬 Life Sciences View papers → 📒 Accounting View papers → 💼 Business Studies View papers → 📈 Economics View papers → 🌍 Geography View papers → 🏛️ History View papers → 📖 English View papers → 🇿🇦 Afrikaans View papers → 🗣️ IsiNdebele View papers → 🗣️ IsiXhosa View papers → 🗣️ IsiZulu View papers → 🗣️ Sepedi View papers → 🗣️ Sesotho View papers → 🗣️ Setswana View papers → 🌾 Agricultural Sciences View papers →

Corresponding examination paper

Examination paper available

Open the corresponding examination paper to practise the questions before reviewing the marking memorandum on this page. Attempt every question under timed conditions for the most realistic preparation.

Electrical Technology Digital Paper 1 (English) →

File details

File size469.1 KB

Pages16

Archived on11 October 2026

File age16d

ContributorFreeMode

Fingerprint4C12F0EA8348

Questions and learner discussion

No questions or discussions have been posted yet.