Agricultural Technology May June 2023 MG Eng hlayiso.com

Downloaded from hlayiso.com SENIOR CERTIFICATE EXAMINATIONS/ NATIONAL SENIOR CERTIFICATE EXAMINATIONS AGRICULTURAL TECHNOLOGY 2023 MARKING GUIDELINES MARKS: 200 These marking guidelines consist of 12 pages. Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 2 DBE/2023 SC/NSC – Marking guidelines SECTION A QUESTION 1 1.1 1.1.1 C 1.1.2 A 1.1.3 B 1.1.4 D 1.1.5 C 1.1.6 A 1.1.7 B 1.1.8 A 1.1.9 A 1.1.10 B (20) 1.2 1.2.1 Rolling.  1.2.2 Hard facing.  1.2.3 Area/Surface.  1.2.4 Reduces/Decreases.  1.2.5 Packing arms.  (10) 1.3 1.3.1 C 1.3.2 F 1.3.3 B 1.3.4 G 1.3.5 H (10) TOTAL SECTION A: 40 Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 3 DBE/2023 SC/NSC – Marking Guidelines SECTION B QUESTION 2: MATERIALS AND STRUCTURES 2.1 2.1.1 THREE reasons why the machining of Vesconite holds no health risk for the person working with it.  Does not contain any asbestos/hazardous fibres.  Does not contain any lead.  Does not give off any poisonous gases/smoke when machined. (3) 2.1.2 TWO products that could be manufactured from Vesconite.  Bushes.  Solid rods.  Wear plates.  Washers. (Any 2) (2) 2.2 2.2.1 The colour of tin.  Silvery-white. (1) 2.2.2 THREE instances where Tin-alloys are commercially used.  Soft solder.  Pewter.  Bronze.  Used as a coating for steel cans.   Food containers. (Any 3) (3) 2.3 How to reduce the magnetism property of stainless steel without affecting its tensile strength.  Add chromium.  Manganese. (Any 1) (1) 2.4 The process of relieving the internal stresses of brass. Use a low-temperature annealing process for 0.5 to 1 hours at 250-300 ºC, dependent on the project size. (2) 2.5 TWO uses of phosphor bronze.  Precision-grade bearings.  Springs. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 4 DBE/2023 SC/NSC – Marking Guidelines 2.6 2.6.1 FOUR household materials where Genkem contact adhesive can be used as an adhesive.  Leather.  Glass.  Wood.  Fabrics.  Rubber.  Metal.  Plastics. (Any 4) (4) 2.6.2 FOUR ways to improve the strength of the joint when using a contact adhesive.  Apply a thin base coat if the surface is very porous.  Apply only a thin layer of adhesive. Avoid thick layer of adhesive on a joint.  Apply adhesive to both surfaces.  Surface must be clean.  Make the surface rough.  Use the correct type of adhesive.  Wait 10 min until dry before joining.  Needs to be heated. (Any 4) (4) 2.7 2.7.1 A type of fence and the reason for using this fence.  Temporary/movable electrical fence.  Used to hold/control/isolate animals for a short period. (2) 2.7.2 The function of the electric fence energizer.  Convert the battery- or mains power into a high voltage pulse/ shock when the animal touches the fence.  (2) 2.7.3 The properties of the isolators that fix the wire of an electric fence to the posts.  Not conduct electricity.  Water resistance.  Durable/long lasting.  Easily replaceable   Easy to use. (Any 3) (3) 2.7.4 Consequences for the person touching an electric fence that has a higher amperage than prescribed by law. The result of too high amperage will be that a person will sustain a shock that can cause injury/tissue damage or heart failure. (2) 2.8 Identify part A and B and the function of each. A – Armoured wire. Protects the cable against mechanical damage. B – Isolation material. Protects the inner cable against water/moist. (4) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 5 DBE/2023 SC/NSC – Marking Guidelines QUESTION 3: ENERGY 3.1 3.1.1 The systems that is suitable to provide electricity for a water pump. A Mountains direct the wind in the wind turbine  OR B Mountains block the wind (2) 3.1.2 THREE advantages of system A (wind) when compare to B (solar).  Compact.  Cheap.  Easy to move.  Low maintenance.  Easy to install.  Can operate when there is no sun.   No need to be cleaned. (Any 3) (3) 3.2 THREE disadvantages of solar geysers  Susceptible to corrosion and scaling.  Very heavy.  High maintenance.  Expensive.  No hot water on a cloudy day or during nighttime.  Can overheat.  Must be orientated correctly.  Can be damaged by bad weather conditions. (Any 3) (3) 3.3 THREE problems associated with a coal power station.  Pollution.  Unreliable.  High maintenance.  Transport of coal is expensive.  Rely on fossil fuels. (Any 3) (3) 3.4 The process of extracting geothermal energy to produce electricity.  Deep holes drilled into the earth to find a geothermal hot spot.  A pipe/sleeve is installed inside the hole.  Cold water is pumped into the hole to be heated by the heat source.  The pressurized steam rises up to the surface.  The steam is channelled to a turbine that begins to turn.  This turbine is connected to the generator that generates the electricity. (6) 3.5 THREE benefits of methanol when used as a supplement fuel for a vehicle.  It offers lower exhaust emissions.  Higher vehicle performance.  It can easily be converted into hydrogen.  Has a lower risk of flammability than petrol. (Any 3) (3) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 6 DBE/2023 SC/NSC – Marking Guidelines QUESTION 4: SKILLS AND CONSTRUCTION PROCESSES 4.1 4.1.1 Cutting of corroded metal where no electricity is available. C (1) 4.1.2 Small compact welding machine used to repair a farm gate in the field, using a small generator to produce electricity. D (1) 4.1.3 Precision cutting without the use of acetylene. A (1) 4.1.4 Welding machine without a welding rod. B (1) 4.1.5 Machine that does not require gas. D (1) 4.2 4.2.1 Correct order: 4, 2, 1, 5, 3, (5) 4.2.2 Total cost of the angle iron used to complete the ramp. Angle iron (32 mm x 32 mm): 2 000 mm+2 000 mm + 500 mm = 4 500 mm (4,5 m)  4,5 m x R95,00 = R427,50 Angle iron: (25 mm x 25 mm) 9 x 400 mm = 3 600 mm (3,6 m)  3,6 m x R43,00 = R154,80 Total cost: R427,50 + R154,80 = R582,30 (Allow for different interpretations during the marking process) (5) 4.3 4.3.1 Identify the component. Gas flow regulator. (1) Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 7 DBE/2023 SC/NSC – Marking Guidelines 4.3.2 The importance of setting the component correctly before proceeding with the welding process.  To prevent spatter.  To ensure a constant weld.  To shield the weld properly.  Without the gas, your the welds will look brown, spattered and just generally not very nice.  To prevent porosity. (Any 4) (4) 4.3.3 Working pressure for the MIG welding process. Between 10 and 25 PSI. (1) 4.4 4.4.1 Description of the overhead arc welding technique.  Use an arc as short as possible.   Weld a number of runs without any lateral movement.   When molten metal starts dripping, slightly reduce the amperage.   Move electrode/gun slightly faster.   Hold electrode/gun in same position as in relation to base metal.  (5) 4.4.2 Safety measure of overhead welding, with a reason.  Operator use leather gloves/fire retartend overall/full face welding helmet/hard hat.  To protect him from molten metal that drips from work piece and might cause serious damage to skin/ body.  (2) 4.5 4.5.1 THREE personal protective equipment that must be worn when performing a task with the oxyacetylene apparatus.  Over all.  Leather gloves.  Leather apron.  Safety boots/Fire resistant shoes.  Leather spats.  Oxy-acetylene welding goggles/helmet. (Any 3) (3) 4.5.2 The gas cylinder that needs to be opened first, with a reason.  Acetylene.  Acetylene is the flammable gas. (2) 4.5.3 Agree with this statement and motivate the answer.  Yes. Gas usage will not be effective when the bottles are lying on its side because the gas will be turned into a liquid making it difficult to pass through the gas pipes. (2) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 8 DBE/2023 SC/NSC – Marking Guidelines QUESTION 5: TOOLS, IMPLEMENTS AND EQUIPMENT 5.1 5.1.1 FOUR mechanical problems that can be experienced with the cutting mechanism.  Blunt/broken blades that cause a blockage.  Blunt/broken cutting rotor.  Seized bearings.  Worn belts and chains.  No lubrication.  Rust on the parts.  Obstructions in the mechanism. (Any 4) (4) 5.1.2 Choose between A and B. Motivate your answer. B (1)  Low initial purchasing cost.  Easy to maintain.  Efficient in small fields.  Lower maintenance cost.  Low running cost.  Not necessary for an extra tractor with a trailer. (Any 2) (3) 5.1.3 The procedures of preparing a machine before working with it.  All grease points must be well greased.  The correct tension must be set for all belts and chains.  Check that all parts are functioning correctly by operating it slowly.  Replace all worn parts immediately especially the cutter blades.  Service according to manufacturer’s specifications.  Lift up all dust release guards.  Check that there is no damage to the blades and that they are sharp.  Check the tyre pressure.  Check the oil and water levels. (Any 5) (5) 5.2 5.2.1 Function of grease nipples. An external grease point to apply the grease for the universal.  (1) 5.2.2 Function of component B. To keep the connected implement in the centre at the back of the tractor or to stabilise the implement. (Any 1) (1) 5.2.3 THREE requirements for screens.  Strong  Not become loose  Weight saving  Must provide adequate/efficient protection.  Bright colour screens for clear visibility. (Any 3) (3) Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 9 DBE/2023 SC/NSC – Marking Guidelines 5.3.1 FOUR factors to be considered before buying a new tractor that needs to be equipped with a front-end loader.  4x4.  Power steering.  Rigidity of construction.  Driver safety and comfort.  Driving power.  Connection points for front loader hydraulics.  Size of front tyres.  Lifting capacity of the front-end loader.  Broken/damaged parts. (Any 4) (4) 5.3.2 FOUR safety precautions when working with a front-end loader against a slope.  Only operate the loader against the vertical angle of the slope.  Stay away from the outer edge when working along high banks and slopes.  Carry the load low to the ground and watch for obstructions on the ground.  Always use the recommended amount of counterweight to ensure good stability.  All tractors used to move bales should have rollover protective structures (ROPS).  Tractor operators should utilize the tractor seat belt at all times when operating the tractor, regardless of the task that is being done. (Any 4) (4) 5.4 5.4.1 Name part A. A- Pick-up mechanism/teeth/needles/fingers.  (1) 5.4.2 Changing bale density on a ram-type baler. By increasing or decreasing the resistance to the hay moving through the baling chamber. (2) 5.4.3 The functions of the slip clutch on the ram-type 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. (3) Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 10 DBE/2023 SC/NSC – Marking Guidelines 5.5 5.5.1 Reason why a differential is fitted on a tractor. Differential is used to divide the rotation equal between the two rear wheels,change the direction of rotationand to affect speed reduction. (Any 2) (2) 5.5.2 Name parts A and B. A - Driving shaft. B - Crown wheel gear. (2) 5.6 Complete the table: SYMPTOM DEFECT ON TRACTOR Black smoke 5.6.1 5.6.2 Water leaks into combustion chamber. Blue smoke 5.6.3 5.6.1  Diesel mixture too rich.  Worn/faulty injectors. (Any 1) (1) 5.6.2 White smoke. (1) 5.6.3  Engine uses oil.  Piston rings are worn.  Cylinder sleeves are worn.  Valve stem seals are worn.  (Any 1) (1) 5.7 5.7.1 Name of the tool. Pneumatic/Air wrench/Drill with a drill attachment. (1) 5.7.2 Power source used. Air/Compressor. (1) [40] Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 11 DBE/2023 SC/NSC – Marking guidelines QUESTION 6: WATER MANAGEMENT 6.1 6.1.1 Reasons why movable sprinkler irrigation systems is the most effective for using on small pieces of irrigation fields.  Inexpensive to purchase.  Low maintenance cost.  Low running cost.  Low labour needs.  The reach of the system is more suitable for small fields because of the limited length of the pipe. (Any 4) (4) 6.1.2 Working of the movable/drum/travelling irrigation system.  The system makes use of polyethylene tubing coiled on a steel drum.  It is powered by irrigation water or a small engine .  The sprinkler is pulled across the field by its own cable system.  The system shuts down automatically when the sprinkler reaches the end of the line.  A large sprinkler attached to the systems applies water in a circular pattern. (Any 4) (4) 6.2 6.2.1 Reason for connecting an irrigation sprinkler to a Variable Rate Applicator. To adapt the rate of water application to various needs as occurring in the irrigation field. (1) 6.2.2 Reasons for the sprinklers positioned at a specific height above the crop.  To limit evaporation.  To ensure effective distribution of the water.  To prevent the sprinkler from interference by the plants. (Any 2) (2) 6.3 Explanation of the term irrigation scheduling. It is the process used by irrigation system managers to determine the correct frequency/flow and duration of watering. (2) 6.4 FOUR aspects that must be considered when choosing a suitable site for building a sceptic tank system.  Must be installed a safe distance from houses, boreholes, traffic and drinking water installations, rivers, streams, underground aquifers.  A sceptic tank must be below ground level.  The drainage field must channel the wastewater away from houses.  Not installed uphill from the house.  Availing wind directions must be considered to accommodate odours or smells. (Any 4) (4) Copyright reserved Please turn over

Downloaded from hlayiso.com Agricultural Technology 12 DBE/2023 SC/NSC – Marking guidelines 6.5 Identification of a drainage system. 6.5 6.5.1 To remove large amounts of rainwater from suburban areas. Chanel drain. (1) 6.5.2 To remove excess water from lawns. Perforated pipes. Drainage ditch. (Any 1) (1) 6.6 Effective use of computer software in an irrigation system.  Prevent over and under irrigation by regulating the water supply.  Remote operation capability.  Variable Rate Irrigation Sprinkler integration/adaptability/capability.  It controls the time, duration and tempo of water supply.  It receives inputs from different monitoring devices.  It receives information from different remote information sources.  Programmable.  Control liquid fertilizer application. (Any 2) (2) 6.7 TWO devices that measure evapotranspiration in a field.  Tensio-meter.  Evaporation pan/class-A pan. (2) 6.8 TWO disadvantages of distillation as a water purifying method.  Distillation cannot remove chemicals.  It is a time consuming method.  Energy consuming method. (Any 2) (2) 6.9 Method of filtration of water with a jug filter system.  Water is poured into the top of the jug.  The water works its way downward through the filtration medium. (2) 6.10 THREE reasons for fitting farm machinery with a GPS.  For precision agriculture.  To pinpoint location of machinery.  Necessary for autonomous machinery.  To apply VRT.  To measure speed for accurate application of fertilizer and chemicals.  (Any 3) (3) [30] TOTAL SECTION B: 160 GRAND TOTAL: 200 Copyright reserved