NATIONAL CERTIFICATE (VOCATIONAL) ENGINEERING TECHNOLOGY NQF LEVEL 2 SUPPLEMENTARY EXAMINATION 2010

Transcription

1 NTIONL ERTIFITE (VOTIONL) ENGINEERING TEHNOLOGY NQF LEVEL 2 SUPPLEMENTRY EXMINTION 2010 ( ) 17 March (X-Paper) 09:00 12:00 REQUIREMENTS: 3 drawing paper andidates will need drawing instruments. This question paper consists of 9 pages and an annexure.

2 ( ) -2- N930(E)(M17)V TIME: 3 HOURS MRKS: 100 INSTRUTIONS ND INFORMTION nswer LL the questions. Read LL the questions carefully. Number the answers according to the numbering system used in this question paper. LL the sketches MUST be neat, clean and in proportion. LL work you do not want to be marked MUST be clearly crossed out. Start each question on a NEW page. Write neatly and legibly.

3 ( ) -3- N930(E)(M17)V QUESTION 1: GENERL 1.1 Indicate whether the following statements are TRUE or FLSE. hoose the answer and write only 'true' or 'false' next to the question number ( ) in the NSWER OOK The ohm is the SI unit of resistance of an electrical conductor. There are two suggested methods used for the first-angle orthographic projection. The 45 line and the circular method. The intermediate tap is used to start the thread. thermometer is an instrument used to measure temperature. The external/outside micrometer allows you to take less accurate measurements than the vernier calliper. 1.2 Various options are provided as possible answers to the following questions. hoose the correct answer and write only the letter ( D) next to the question number ( ) in the NSWER OOK To have a good finish on metal, you must use a D rough file. second cut file. smooth file. bastard file Which lines can a person use to indicate the hidden detail in firstangle orthographic projection? D Object lines Dimension lines entre lines roken lines This useful instrument has three heads that are used separately and are held to a beam by a nut: D The surface plate Jenny callipers The combination set Dividers When using orbital sander D use a dust mask and goggles. push the sander down hard. use one hand to wipe the dust off. never use clamps for the workpiece.

4 ( ) -4- N930(E)(M17)V hydrometer is a tool for measuring D a level of a liquid in a glass. density of liquids. pressure liquids. acid on batteries. 1.3 omplete the following sentences(s) by filling in the missing word(s). Write only the word(s) next to the question number ( ) in the NSWER OOK The is used to support round shafts for marking. Kilometres are larger units than metres. Multiply by the number of metres in 1 kilometre, which is. G-clamps are made from steel. holds the blade of a bandsaw machine in position. The depth micrometer is supplied with a number of interchangeable for measuring extra depth. 1.4 Give ONE word/term for each of the following descriptions. Write only the word/term next to the question number ( ) in the NSWER OOK It is defined as the workdone or energy transferred when a force of 1 Newton is exerted through a distance of 1 metre in the direction of the force. It is used mainly to mark the centre of holes that are to be drilled. ir leakage can cause a dramatic drop in performance of the machine. n engineering precision measuring tool that is used to measure inside diameters or distance between two inside points. n instrument with an adjustable ruler and has a spirit level. [20]

5 ( ) -5- N930(E)(M17)V QUESTION 2: ENGINEERING HND TOOLS Name the hand tools shown in FIGURE 1 and FIGURE FIGURE 1 FIGURE Name the TWO parts marked on the bench vice in FIGURE Which hand tools will you use for the following: FIGURE To drive out a pin from a hole To fix a 1,2 mm thick piece 2.4 State ONE safety use for each of the following hand tools: llen key Flat chisel Hack saw 2.5 Give TWO reasons for the failure of hacksaw blades. 2.6 You are a foreman at an engineering company, and walks past a worker who is busy using a file without a handle What will you do as a foreman? What guidance will you give to the worker?

6 ( ) -6- N930(E)(M17)V 2.7 Explain how you would take care of the storage of your hacksaw after it has been used. Indicate as well the matching consequences of its improper storage How you take care The matching consequences of improper care [17] QUESTION 3: ENGINEERING POWER TOOLS. 3.1 Name TWO engineering power tools you would use with the following accessories: Drill bit Masonry disk 3.2 State the THREE parts of a hydraulic press drill marked in FIGURE FIGURE State ONE function of each of the following power tools: Welding machine ngle grinder Sanding machine 3.4 Name any THREE types of pneumatic power tools. (3) 3.5 State TWO corrective measures you would apply if your pedestal grinding machine wheel wobbles.

7 ( ) -7- N930(E)(M17)V 3.6 State TWO methods you would apply when removing mushroom heads from your tool. 3.7 Your compressor is running and you notice that its hose is broken. What consequence would be brought about by this defect and what action would you take to correct this? [17] QUESTION 4: ENGINEERING MESURING EQUIPMENT Name any THREE engineering measuring instruments. Draw a combination square and label THREE parts of the instrument. The ruler of the combination square you are using is loose, which part of this instrument would you adjust and which direction would you adjust it to? You and your workmate were measuring the inside height of an electric distribution board, suddenly the hook of this instrument is trapped in the live electric wires, and your workmate gets shocked. What would you do and what was the name of the instrument used? (3) (3) (3) 4.5 What is the first safety measure you would do before using an engineer's square? [12] QUESTION 5: ENGINEEERING PREISION MESURING EQUIPMENT 5.1 Name the TWO parts marked and on the vernier calliper in FIGURE FIGURE 5

8 ( ) -8- N930(E)(M17)V State ONE safety measure when using the vernier calliper protractor. State TWO steps in reading the measurement of an object that was measured with an external/outside micrometer. State TWO aspects of care, maintenance and storage of the telescopic gauge. [7] QUESTION 6: SI UNITS OF MESUREMENT 6.1 How many millilitres are there in 1 litre? 6.2 Identify the following SI units of measurement: G M 6.3 Define the following terms: Power Electrical Potential 6.4 alculate the force needed for a body mass of 500 grams which is accelerated at 3 m/s. HINT: force = mass x acceleration [7] QUESTION 7: ENGINEERING MRKING OFF EQUIPMENT What is the function of a level gauge? Name any TWO components of combination set. Give a detailed explanation or a sketch on how to use the odd leg callipers. (Free-hand drawing) (3) [7] QUESTION 8: SI ENGINEERING DRWING 8.1 FIGURE 6, NNEXURE 1 (attached), is an isometric view of a machine part. Draw to a scale of 1:2 in the first-angle orthographic projection, the following: front view () top view () left view ()

9 ( ) -9- N930(E)(M17)V Show LL the hidden detail. Insert the dimensions in the three views. Insert the projection symbol in the space below the left view. (3) (2 [13] TOTL: 100

10 ( ) -10- N930(E)(M17)V NNEXURE 1 FIGURE 6