AGRICULTURAL TECHNOLOGY
GRADE 12 
NSC EXAMS
PAST PAPERS AND MEMOS
NOVEMBER 2018

MEMORANDUM 

SECTION A 
QUESTION 1 
1.1
1.1.1 C✔✔ (2)
1.1.2 D✔✔ (2)
1.1.3 B✔✔ (2)
1.1.4 D✔✔ (2)
1.1.5 B✔✔ (2)
1.1.6 A✔✔ (2)
1.1.7 C✔✔ (2)
1.1.8 C✔✔ (2)
1.1.9 C✔✔ (2)
1.1.10 A✔✔ (2)  (10 x 2) (20) 
1.2
1.2.1 one way valve/non return valve✔✔ (2)
1.2.2 timing✔✔ (2)
1.2.3 Alternator/invertor✔✔ (2) 
1.2.4 Hopper/inlet trough/Thought/A uger/Conveyer belt.✔✔ (2) 
1.2.5 Nipple/Pump/Gun✔✔ (2) (5 x 2) (10) 
1.3
1.3.1 A✔✔ (2)
1.3.2 C✔✔ (2)
1.3.3 H✔✔ (2)
1.3.4 D✔✔ (2)
1.3.5 B✔✔ (2) (5 x 2) (10) 

TOTAL SECTION A: 40

SECTION B 
QUESTION 2: MATERIALS AND STRUCTURES  
2.1
2.1.1 TWO elements that decrease magnetism in stainless steel.

• Chromium,✔ Nickel✔ and Manganese✔ (Any 2) (2)

2.1.2 THREE properties of copper. 

• Excellent conductor of electricity✔
• Good conductor of heat✔
• Strong✔
• Ductile✔ 
• Easily joined by soldering or brazing✔ 
• Hygienic✔ 
• Easy to alloy✔ 
• Resists corrosion✔ 
• Durability✔ 
• Soft metal✔
• Pliable✔ (Any 3) (3)

2.1.3 TWO requirements that determine the composition of brass. 

• Manufacturing requirements✔
• Application requirements/purpose✔
• ost effectiveness✔ (Any 2) (2)

2.1.4 Properties of Tin. 

• Silvery-white✔
• Soft✔ 
• Malleable metal✔
• It can be highly polished✔
• An oxide film form on exposed surfaces ✔ 
• When tin is bent, a 'tin cry' is heard, due to the breaking of crystals✔
• Prevent corrosion✔
• Prevents contamination of food✔
• Easy to blend/ Use as alloy✔
• Conduct electricity✔ (Any 3) (3)

2.2
2.2.1 Description of 'elasticity' of adhesives. 

• Degree of hardness and brittleness of the adhesive when they dry-off.✔
  Must stay elastic even after it dried. ✔ (2)

2.2.2 THREE recommendations to improve the strength of an adhesive. 

• Apply a thin base coat if the surface is very porous✔
• Apply only a thin layer of adhesive✔
• Apply adhesive to both surfaces✔
• Avoid thick layer of adhesive on a joint✔
• Avoid thick layer of adhesive on a joint✔
• Surface must be clean✔
• Make the surface rough✔ 
• Correct adhesive✔ 
• Wait till dry before joining✔ 
• Correct kind of adhesive✔ (Any 3) (3) 

2.3 THREE safety precautions which are applicable to glass fibre. 

• Catalyst and accelerator should always be stored separately.✔
• Remove all resin catalyst and accelerator from skin.✔
• Wear hand gloves if skin is sensitive.✔
• Glass fibre matting has small pieces of fibre that can penetrate the skin.✔
• Use nose mask (avoid breathing in glass fibre) ✔
• Use protective glasses (protect the eyes).✔
• Use acetone in a well-ventilated room.✔
• Handle resin castings carefully, they are brittle and have sharp edges.✔
• Wear overall/ protective clothing.✔ (Any 3) (3) 

2.4 THREE advantages of Vesconite. 

• Easy to fit and remove.✔
• Does not corrode and is non-conductive.✔
• Will not wear shafts and liners like traditional materials.✔
• Resistant to a wide range of materials.✔ 
• Bearings will not seize on the axle✔ 
• Will not expand in water✔ 
• Does not delaminate✔ 
• Low friction coefficient✔ 
• Can be used without any lubrication✔ 
• Low maintenance✔ (Any 3)  (3) 

2.5 THREE substances that do not have an influence on a Teflon coating. 

• Asphalt✔ 
• Dyes✔ 
• Greases/oil✔ 
• Glue✔ 
• Latex✔ 
• Lacquers✔ 
• Paints✔ 
• Acids/chemicals/water✔ (Any 3) (3) 

2.6 THREE safety standards of insulation material used in buildings.

• Must not be harmful or dangerous to people when inhaled or touched.✔
• Should not burn easily.✔ 
• Rodents and insects must not be able to eat it or build their nests in it.✔
• Must not be heavy./Must be lightweight.✔  (Any 3)  (3) ∙ 

2.7
2.7.1 THREE causes of short circuit that appears on an electric fences. 

• Vegetation touching the fence✔
• Leakage✔
• Faulty joints✔
• Broken wires✔
• Faulty insulators✔
• Moist conditions✔ 
• People and animals✔
• Lightning✔ (Any 3)(3)

2.7.2 Placing of safety signs on an electric fence. 

• Gates/doors✔
• Fence wire✔ 
• Fence poles✔ 
• Spacing✔
• Where people came in contact with the fence✔ (Any 2)  (2) 

2.7.3 THREE functions of the covering material used on underground  electric fence cables. 

• Protect cable against mechanical damage (tractors, spades, etc.)✔
• Protect from corrosion✔
• Isolation✔
• Protect cable against water/moist✔ (Any 3) (3) [35]

QUESTION 3: ENERGY  
3.1
3.1.1 Explanation of the requirements of a suitable location to install a wind  turbine. 

• Wind turbines require a substantial wind speed to generate electricity  efficiently.✔
• The faster the wind, the more output in watts you can generate, but you  cannot go over your turbines capacity.✔
• The location must be surrounded by open fields.✔
• If there are any large hills or mountains close by, then the placement of  wind turbines may not be your best option.✔
• If there is a forest or collection of trees nearby, then you cannot optimize  wind energy.✔
• Make sure your turbine is facing the most common wind direction.✔
• Not close to overhead electric cables.✔
• Not close to houses.✔ (Any 4) (4)

3.1.2 THREE advantages of wind energy. 

• Wind power has no fuel costs.✔
• Low or negligible costs for maintenance.✔ 
• No carbon tax costs.✔
• Natural gas and oil imports can be reduced.✔
• Wind turbines are emissions-free, which means they do not  contribute to air pollution.✔
• Wind is a renewable energy source unlike fossil fuels, which are an  exhaustible source of energy.✔
• As a result, large numbers of wind turbines could reduce  dependence on other energy sources, providing a more  dependable source of energy in the long term.✔
• Wind energy is much cheaper than other sources of energy.✔
• Wind turbines are a great resource to generate energy in remote  locations, such as mountain communities and remote  countryside.✔
• Wind power has no clean-up costs, fossil fuels do.✔ (Any 3) (3) 

3.2 FOUR factors that will have a negative influence on the efficiency of a photo voltaic solar panel system. 

• The cell is not working to its full potential due to some electrons being lost.✔
• When the electrons release heat; the panel also becomes warm, interfering  with other aspects of the solar cells.✔
• Number of solar panels determines the efficiency of the system.✔ 
• Expensive natural energy technologies produce more efficiently than  cheaper ones.✔
• Obviously nearer the equator, you will receive a slightly better output with a  given cell (location).✔
• Solar cells should always be facing the direction of the sun.✔
• No objects blocking the sun’s rays.✔
• Electrical short✔ (Any 4) (4) 

3.3 TWO problems associated with the generation of geothermal energy. 

• You must not pump too much cold water into the earth, as this could cool  your geothermal heat source.✔
• Geothermal power plants must be protected from escaping gases from  deep within the earth.✔
• Location of the geothermal power plant.✔
• Cost of generating electricity.✔
• Water pollution✔ 
• Cost✔
• Contamination of the water✔ (Any 2) (2)

3.4 The material that is suitable for manufacturing Biofuel and an explanation.

• Any plant matter or animal waste✔ that can combust.✔Animal waste✔ (2)

3.5 TWO processes that are used in the manufacturing of ethanol. 

• Fermentation✔
• Distillation✔ (2)

3.6 THREE advantages of methanol as an alternative fuel. 

• It offers lower exhaust emissions.✔
• Produces higher vehicle performance.✔
• It can easily be made into hydrogen.✔
• Can be used in methanol direct fuel cells.✔
• Methanol has a lower risk of flammability than gasoline.✔ (Any 3)(3) [20] 

QUESTION 4: SKILLS AND CONSTRUCTION PROCESSES  
4.1 Comparison of MIG-welding and Arc-welding under given headings.  (8) 

4.2
4.2.1 Function of the MIG part. 

• This device adjusts the tension ✔on the welding wire.✔
• Wire Feeder✔✔ (Any 1) (2) 

4.2.2 FIVE safety measures that must be followed when welding with  the MIG-welding machine. 

Related Items

• Remove all materials that can catch fire.✔
• Protect eyes by wearing a welding shield/screens.✔ 
• Wear welding gloves to handle hot metal.✔ 
• Wear leather/cotton apron for UV protection and heat.✔ 
• Weld in well-ventilated area for fumes.✔ 
• Prevent burns or sparks on the face by wearing a welding shield.✔ 
• Do not wear open shoes.✔ 
• Stand on rubber matt.✔ (Any 5) (5) 

4.3 THREE different types of welding movements that can be used for arc welding run and make a drawing of each welding figure. 
(Any 3 x 2) (6)
4.4 Description of the cutting process that must be followed to ensure a safe and  clean cut when cutting a 10 mm steel plate with the oxy-acetylene cutting  torch. 

• Set the required gas flow on the cylinders.✔
• Set the oxy-acetylene torch according to the need.✔ 
• Heat the material up to red hot.✔ 
• Press the oxygen lever to blow away the melted metal.✔ (4) 

4.5 Explanation of the influence that water/moisture has on the plasma cutter  nozzle. 

• Water entering the torch nozzle can cause a short circuit.✔ The short circuit  causes damage to the nozzle because of the internal arcing that takes place.✔ Unevenness of the flame.✔ (Any 2) (2) 

4.6 Design of a cattle handling facility for 50 cattle consisting of one big holding kraal, three smaller kraals, a crush pen and functional gates. 
MARKING INSTRUCTIONS: 

• Effective design (one big kraal ✔, three smaller kraals ✔ and a crush pen ✔) (3)
• Enough gates to facilitate the handling process.✔ (1)
• Placing/functionality of the gates. ✔ (2)
• Measurements/headings.✔ (1)
• Entrance gate.✔  (1) 
  

[35]

QUESTION 5: TOOLS, IMPLEMENTS AND EQUIPMENT  
5.1
5.1.1 THREE factors with a short explanation of each that have an  influence on the depth control system of a tractor. 

• Soil resistance:✔ On sandy soils the plough will go deeper. In  hard soil the plough will not penetrate easily.✔
• Forward speed of the tractor:✔ When ploughing at high  speed, the plough will not penetrate effectively. ✔
• Ploughing depth:✔ Soil will have a great influence on the  plough when ploughing deep. ✔ (6) 

5.1.2 THREE items on the tractor that the driver must inspect before  starting the tractor.  

• Fuel level✔
• Water level✔
• Oil level✔
• Tyre pressure✔ 
• Any liquid leaks✔(Oil, water or fuel) 
• Any repairs needed ✔(Electrical etc.) 
• Loose electrical wires✔
• Battery water level✔
• All safety guards in position✔
• Any parts of a tractor✔ (Any 3)(3) 

5.2 FIVE advantages of modern combine harvesters over manual harvesting  methods. 

• Very quick way of harvesting the crop.✔
• Very reliable method of harvesting.✔
• Economical.✔
• Labour saving.✔
• Accurate record keeping.✔
• Computers do the whole harvesting processes with little input from  the driver.✔
• Single operation.✔ (Any 5) (5) 

5.3 FOUR requirements that safety screens on farm machinery must comply  with. 

•  Safeguard the equipment✔
• Safeguard the operator✔ 
• Removed and replaced easily✔
• Must appear neat✔
• Must be properly installed.(not loosened while in motion)✔ 
• Weight saving✔(light)
• Keep out all undesired material✔
• Strong✔ 
• Not broken✔ 
• Safety signs on screens. (Any 4)(4) 

5.4 5.4.1 The device (A or B) that will be found in a ripper to protect the teeth from braking when it gets stuck behind a rock or plant root.  

• A✔ (1) 

5.4.2 THREE functions of the slip clutch found in the drive mechanism of  a baler. 

• Prevent heavy objects from being taken into the baler.✔
• Protect the pick-up if it is impeded by anything.✔
• Protect the auger if it becomes overloaded.✔
• Moving parts are protected. ✔ (Any 3) (3) 

5.4.3 The device, in diagram B, that enables the driveshaft connected to the slip clutch to work at an angle. 

• Universal joint✔ (1)
• U coupling✔ 

5.5 FIVE factors that must be taken into consideration when planning the  purchase of a new tractor. 

• Driving power✔
• Local availability of parts and service✔ 
• Rigidity of construction✔ 
• Simplicity of control mechanisms✔ 
• Driver comfort✔ 
• Versatility✔ 
• Proven reliability and durability✔ 
• Type of drive necessary✔ 
• Cost/Price of the tractor✔ (Any 5) (5) 

5.6 Comparison between the V-belt and flat belt`s under the headings that  are given.  (8)

5.7 The effect that the presence of air has on the working of a hydraulic  system. 

• The air is compressible✔ that will lead to higher pressure in the hydraulic  system✔ and can cause pipes to burst.✔
• The piston on the receiving side will not  react as required because there is no direct pressure. ✔
• The system will shudder✔ (4)  [40] 

QUESTION 6: WATER MANAGEMENT 
6.1 THREE advantages of system A over system B.  

• This system is less expensive to install.✔
• It consists of sections that can be easily disconnected.✔
• They are used for small or square shaped fields.✔
• Less crop damage.✔ 
• No electricity needed.✔ 
• Can easily been moved to another land. ( Any 3) (3) 

6.2 THREE sources that a 'Smart Controller' uses to determine local weather  conditions. 

• Soil sensor✔
• Rain sensors✔ 
• Satellite feed ✔ 
• weather station✔ 
• Internet/Wi-Fi✔ 
• Evaporation pan✔ 
• Radar✔ 
• Moist sensors✔ ( Any 3) (3) 

6.3 Recommendation to a farmer on to consider before choosing a type of  irrigation system for a piece of land. 

• The size of the area to be irrigated.✔
• The shape of the land.✔ 
• Obstructions, such as trees or rocks.✔ 
• How deep the soil needs to be watered.✔ 
• How much time and effort is available to use the system.✔ 
• Type of crop under cultivation. ✔ 
• Cost ✔
• Amount of water available✔ (Any 3) (3) 

6.4 THREE instances where flood irrigation would be preferred over sprinkler  irrigation. 

• When water supply is of abundance.✔
• Surface gradient cannot lead to erosion.✔ 
• Infiltration tempo is constant.✔ 
• Where soil has good water absorption.✔ 
• Landscape has a suitable slope.✔
• Initial setup cost is low.✔
• Finance available✔
• When land is next to a non-consistent river✔ (Any 3) (3)

6.5
6.5.1 The mistakes in the design drawing of a septic tank. 

• Inlet must be higher than the wall.✔
• Outlet must be lower than the wall. Make the wall higher✔ (2) 

6.5.2 THREE items that must NOT be flushed down a septic tank drainage system. 

• Plastics or non-degradable materials✔
• Cigarette buds, rags etc. should get into the tank✔ 
• Disinfectants should be used✔ 
• Paper or sanitary towels that does not dissolve easily✔
• Bleaches✔ 
• Oils or fatty substances✔ 
• Drain openers✔  (Any 3) (3) 

6.5.3 What will happen in a septic tank drainage system if the bacteria are  destroyed? 

•  The system will simply act as a holding tank for waste.✔
• It will fill up with waste.✔ 
• Natural decomposition will not occur.✔   (Any 2) (2)

6.6 TWO factors that will determine the cleaning of a septic tank. 

•  The amount of waste water that goes through the system each day.✔ 
• The amount of excess fats, rinds and other similar garbage in the drain.✔
• Working of the bacteria.✔ 
• Seize of the tank.✔ (2) 

6.7 Calculation of the flow rate of a tank (litre per minute) by using the data  below:  
(Show all calculations) 
The capacity of the tank is 20 k ℓ 
It took 40 minutes to fill the tank to the top. 
Use the formula:

• Flow rate = capacity 
                       time 
  = 20 x 1000✔ 
          40 
  = 20000✔ 
       40 
  = 500✔ ℓ/minute✔ (4)

6.8 Function of GPS, GIS and VRT.  (3)

6.9 Components on the whole house filtering system that must be checked and  replaced on a regular basis. 

• Filter elements/cartridges.✔
• O-rings.✔ 
• Salt in the water softener.✔ 
• Pipes✔ 
• Sieve✔ 
• Pumps✔ 
• Tanks✔ 
• Taps✔ 
• Valves✔  (Any 2) (2) [30] 

TOTAL SECTION B: 160
GRAND TOTAL:  200