AGRICULTURAL TECHNOLOGY
GRADE 12 
NSC PAST PAPERS AND MEMOS
FEBRUARY/MARCH 2017

INSTRUCTIONS AND INFORMATION 

1. GENERAL INSTRUCTIONS AND INFORMATION
   1.1 This question paper consists of TWO sections, namely SECTION A  and SECTION B.
   1.2 BOTH sections are COMPULSORY.
   1.3 Answer ALL the questions in the ANSWER BOOK.
   1.4 Number the answers correctly according to the numbering system  used in this question paper.
   1.5 You may use a non-programmable calculator.
   1.6 Write neatly and legibly. 
2. SECTION A: SHORT QUESTIONS
   2.1 This section consists of THREE questions.
   2.2 Follow the instructions when answering the questions.
3. SECTION B: STRUCTURED LONG QUESTIONS 
   3.1 This section consists of FIVE questions.
   3.2 Start EACH question on a NEW page.

QUESTIONS 

SECTION A 
QUESTION 1 
1.1 Various options are provided as possible answers to the following questions.  Write down the question number (1.1.1–1.1.10), choose the answer and make  a cross (X) over the letter (A–D) of your choice in the ANSWER BOOK. 

1.1.1 Plasma cutting machines may be used to cut … sheets. 

1. aluminium 
2. copper 
3. stainless steel
4. brass (2) 

1.1.2 A gas mixture used to cut thick steel with the plasma cutting  machine, which is preferred because of its ability to produce high  temperatures: 

1. Argon hydrogen 
2. Oxyacetylene
3. Nitrogen oxide
4. Carbon dioxide (2) 

1.1.3 ONE of the following metals may be arc-welded successfully: 

1. Zinc
2. Brass
3. Copper
4. Mild steel (2) 

1.1.4 The pipe-weld joining method used most commonly when  manufacturing a farm gate is the … roll position. 

1. butt joint
2. open butt joint
3. spot weld
4. overlap T-joint (2) 

1.1.5 The function of the gas shield around the welding bead when  MIG welding: 

1. Prevents oxidation
2. Cleans the weld bead
3. Ensures the correct temperature for welding
4. Ensures a faster welding speed (2)

1.1.6 This metal CANNOT be welded with the MIG welding machine: 

1. Aluminium
2. Stainless steel 
3. Mild steel
4. Titanium (2) 

1.1.7 Using a/an … is cost effective and an easy way to conduct aerial  surveys of a farm.  

1. aeroplane
2. helicopter
3. drone
4. satellite (2) 

1.1.8 Modernisation of farm implements implies … 

1. environmentally safe implements that leave a green footprint.
2. industrialisation of a farm.
3. that all implements must adhere to uniform standards.
4. a switch to robotics and computers. (2) 

1.1.9 The main function of the hopper on a hammer mill is to … 

1. facilitate the feeding process.
2. pulverise the fodder.
3. house the guard plates and wearing plates.
4. determine the size of the final ground product. (2) 

1.1.10 Solar power technology is environmentally friendly because  no … is released into the atmosphere. 

1. hydrogen vapour
2. water vapour
3. pollution 
4. heat (2) 

1.2 Change the UNDERLINED word(s) in each of the following statements to  make the statements TRUE. Write only the word(s) next to question number  (1.2.1–1.2.5) in the ANSWER BOOK, for example 1.2.6 Tractor. 

1.2.1 The large overhead water pipe of a centre pivot is manufactured  from copper. (2) 
1.2.2 Wind power converts the kinetic energy present in wind into  chemical energy and then into electrical energy. (2) 
1.2.3 Standardisation in agriculture is less time-consuming and more  cost-effective than working by hand. (2) 
1.2.4 Non-stick pots and pans used for cooking are coated with bakelite. (2) 
1.2.5 Bacteria in a septic tank prevent the breakdown of solids into  a liquid form. (2)

1.3 Choose a word/term from COLUMN B that matches the description in  COLUMN A. Write down only the letter (A–G) next to the question number  (1.3.1–1.3.5) in the ANSWER BOOK, for example 1.3.6 H. 

(5 x 2) (10) 
TOTAL SECTION A: 40

SECTION B 
QUESTION 2: MATERIALS AND STRUCTURES 
Start this question on a NEW page. 
2.1 When certain elements are added to stainless steel they may cause changes  in the properties of the stainless steel. 

2.1.1 Name THREE influences of nickel on stainless steel. (3) 
2.1.2 Name the final product formed when two or more pure metals are  melted together. (1) 

2.2 What happens to a metal when it is annealed? (1)
2.3 Give TWO reasons for removing flux residues after soft soldering. (2) 
2.4 Give a reason why brass, which has been heated to a red hot temperature,  should NOT be cooled in cold water. (1) 
2.5 State THREE properties of tin. (3)
2.6 Adhesives are used daily to join materials. 

2.6.1 Define the term adhesion. (1) 
2.6.2 Name TWO important aspects that must be considered when an  adhesive is chosen. (2) 

2.7 Describe FOUR precautionary measures to consider when working with  glass fibre. (4) 
2.8 A vesconite bush is removed easily from the shaft.  Give TWO reasons to support this statement. (2)
2.9 The photograph below shows an electric fence. Answer the questions that  follow. 

2.9.1 Name THREE factors which may cause interference on an  electric fence. (3) 
2.9.2 According to safety regulations, what should be installed in an electric fence where it crosses the path of pedestrians? (2) 
2.9.3 Name THREE types of material that may be used as isolators between the wires and posts of an electric fence to prevent  short circuits. (3) 
2.9.4 State TWO types of batteries which may be used as a power  supply for an electric fence. (2) 

2.10 The wires of an electric fence must be very strong because of the enormous  strain in the wires.  

2.10.1 Name the type of wire used for erecting an electric fence. (1)
2.10.2 What is the minimum thickness of the wires for an electric fence? (1) 
2.10.3 Name a cost-effective process that may be used to protect the iron  components of an electric fence against corrosion. (1) 
2.10.4 Name TWO factors which must be taken into consideration when  installing a fence energiser. (2)

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QUESTION 3: ENERGY 
Start this question on a NEW page. 
3.1 A photograph of a wind turbine is shown below. Answer the questions  that follow. 

3.1.1 Name THREE aspects to consider when selecting a wind turbine  to generate power for an electric fence on a game farm. (3) 
3.1.2 Describe FOUR advantages of using a wind turbine to generate  electrical energy. (4) 

3.2 Solar energy is one of the greatest sources of alternative energy, but it is also  a source that is mostly underutilised. 

3.2.1 Name TWO types of energy that are generated directly from solar  energy and give an example of a device that can convert this  energy effectively. (4) 
3.2.2 Name the component that is used to change direct current (DC)  generated by photovoltaic cells into alternating current (AC). (1) 
3.2.3 What is the most common semiconducting material used to  manufacture solar panels? (1)

Related Items

3.3 Methanol is used in various fuel applications on a farm. 

3.3.1 Name the gas that is used to manufacture methanol fuel and state a source of this gas. (2) 
3.3.2 State TWO advantages of methanol fuel. (2) 

3.4 A geothermal power plant uses steam from deep within the earth to generate  electricity. Describe how this steam is used to generate electricity. (3)

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QUESTION 4: SKILLS AND CONSTRUCTION PROCESSES 
Start this question on a NEW page. 
4.1 MIG welding is easy because it requires less skill than conventional  arc welding. 

4.1.1 Name THREE settings on the MIG welding machine that should be  adjusted before starting a welding project. (3) 
4.1.2 You can tell a fair amount about the quality of a MIG welding  process by the way it sounds. Describe the correct sound that the  MIG welding process should make. (2) 
4.1.3 What is wrong with the setting of the MIG welding machine if the  welding operator burns holes into the work piece? (1) 

4.2 The picture below shows an oxyacetylene welding apparatus. Answer the  questions that follow. 

4.2.1 Explain the procedure to extinguish an oxyacetylene flame when  a welding job has been completed. (5) 
4.2.2 Describe the symptoms experienced when welding vapours from  galvanised steel has been inhaled and give the name of this kind  of poisoning. (2)

4.3 You have to install burglar proofing for a room in which poisonous insecticides  are stored.  
The window is 800 mm high and 600 mm wide.  
The burglar proofing should consist of two vertical and three horizontal bars. 
You may only use 10 mm square bars.  
The cost of the metal is R5,00 per metre. 

4.3.1 Make a neat, freehand drawing of the window frame and indicate  the placing of the burglar proofing.  
Marks will be awarded as follows:  (4) 

4.3.2 Calculate the cost of the materials that will be used to manufacture the burglar proofing. (Show ALL calculations.) (3) 

4.4 Discuss the overhead arc-welding technique when the metal trusses of  a shed are being welded. (5) 
4.5 Name THREE circumstances when the horizontal square butt welding joint  will be used. (3) 
4.6 A plasma jet creates high amounts of ultraviolet radiation that may harm the eyes.  

4.6.1 What is the correct source of information to consult to choose the  correct eye protection for plasma cutting? (1) 
4.6.2 Give THREE advantages of a plasma cutting machine compared to  an oxyacetylene cutting set. (3) 

4.7 Plasma cutting machines have built-in regulators with air filters to remove  moisture or other contaminants. Explain the results if the air filters of the plasma cutting machine become  saturated with moisture. (3)

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QUESTION 5: TOOLS, IMPLEMENTS AND EQUIPMENT 
Start this question on a NEW page. 
5.1 Describe FIVE safety measures applicable when using a push lawn mower. (5) 

5.2 A power take-off shaft is shown below. Answer the questions that follow.  

5.2.1 Name the device that allows the power take-off shaft to operate  at an angle. (1) 
5.2.2 Safety screens must always be used when working with a power  take-off shaft so that people are not injured when it is being  operated.  State TWO requirements that these safety screens should  comply with. (2)

5.3 A combine harvester is shown below. Answer the questions that follow. 

5.3.1 Why would a combine harvester break the maize kernels during  the threshing process? (2) 
5.3.2 Why would the maize kernels and the chaff be blown out the back  of the harvester? (2) 

5.4 The photograph below shows a hammer mill used on a farm to pulverise feed. 

Name the part of the hammer mill responsible for EACH of the following actions: 

5.4.1 Pulverising feed (1)
5.4.2 Determining the size of the final ground product (1)
5.4.3 Separating the ground material effectively from the air (1)

5.5 Describe the procedure that must be followed when the silage cutter shown  below is prepared for use. (5) 

5.6 Safety is very important when working with the front-end loader shown below.  

Name the preventative measures that the operator must take to prevent the  following injuries: 

5.6.1 The driver is injured by a falling bale (1)
5.6.2 Bystanders are injured by a bale falling from the loader (1) 
5.6.3 The front-end loader falls on its side while it is moving up a steep  slope (1) 

5.7 A ram-type baling machine is shown below. Answer the questions that follow. 

5.7.1 Name TWO safety mechanisms used on the ram-type baling  machine. (2) 
5.7.2 Describe the function of the auger in the ram-type baling machine. (3)

5.8 Name the parts that are used to connect the implement below to the tractor. (3) 

5.9 Name the THREE shafts found in the manual gearbox of a tractor. (3) 
5.10 Compare the two types of drive belts shown below by redrawing and  completing the table in the ANSWER BOOK.  

(6) 

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QUESTION 6: WATER MANAGEMENT 
Start this question on a NEW page. 
6.1 South Africa is a country where water shortages occur frequently. Farmers  must use more efficient irrigation systems to conserve water. A farmer wants to water one hectare of land with drip irrigation. A sketch of  the one-hectare field with a closed network of pipes is shown below.  

6.1.1 Calculate the length and cost of the pipes you will need for  the field. The pipes are 100 m long each and will be connected and  evenly spread across the field. The price of the pipes that will be  used is R6,50 per metre. (3) 
6.1.2 Calculate the total cost of the T-joints and elbows that you will  need if there are 19 T-joints at R8,00 per T-joint and 4 elbows at  R6,50 per elbow. (3)

6.2 Explain the function of a one-way irrigation valve. (3)
6.3 State FOUR advantages of sprinkler irrigation over flood irrigation. (4) 
6.4 Briefly describe the safety feature built into the centre pivot irrigation system  to prevent the centre pivot from falling when a wheel gets stuck. (3) 
6.5 Give THREE important reasons why a farmer would prefer drip irrigation to  an overhead irrigation system. (4) 
6.6 Name TWO types of equipment that may be used to determine evaporation levels in a specific field. (2) 
6.7 Name THREE types of irrigation systems that may be used by farmers  to irrigate large fields. (3)
6.8 State the main problem commonly experienced by farmers who irrigate fields  from rivers. (1) 
6.9 Name the kind of capital represented by EACH of the following:

6.9.1 Irrigation pipeline between the water source and the centre pivot (1)
6.9.2 Irrigation system water filters (1)
6.9.3 Wages of the labourers (1) 
6.9.4 Tractor (1)

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TOTAL SECTION B: 160
GRAND TOTAL:  200