Metalwork - Exam Papers - HL - Paper - 1998

100 Marks

INSTRUCTIONS

1. Answer Question 1, Sections A and B and three other questions.
2. All answers must be written in ink on the answer book supplied. Diagrams should be drawn in pencil.
3. Squared paper is supplied for diagrams as required.
4. Please label and number carefully each question attempted.

1.
(40 Marks)

SECTION A - 20 MARKS
COMPULSORY
Answer any five questions

(a) Describe in two sentences, the contribution made to technology by one of the following people :
Henry Ford,
John Holland,
Father Nicholas Callan.

(b) The diagram shows part of a four-stroke spark ignition engine.

  1. What material would be suitable for the manufacture of part G ?
  2. What is the purpose of part G ?

(c) Identify and name part E or D and state its function.

(d) Explain, with the aid of a sketch, the operation of part A.

(e) With the aid of a sketch, show how part F is attached to part G.

(f) An electric engraver has the following specification 50W - 220V - AC. Explain the meaning of any two of these.

(g) Examine the electronic circuit shown.

  1. Identify and name any two components.
  2. Draw the symbol for each of the two named and state the function of each.
Components
Transistor
Light Dependent Resistor (LDR)
Switch
Variable Resistor
Bulb

SECTION B - 20 MARKS
COMPULSORY
Answer any five questions

The drawing shows the front elevation of a Thermostatically Controlled Candle Extinguisher based on a bi-metallic mechanism (part G).
(a) With the aid of sketches, describe how the bi-metallic mechanism operates.

(b) Describe the steps involved in the manufacture of part A.

(c) State the correct name for part D. Give an example of the specification required for the purchase of items like part D.

(d) What are the purposes of parts C and H ?

(e) Name another appliance which makes use of a bi-metallic mechanism.

(f) Show, by means of a sketch, how part H is attached to the extinguisher arm, part J.

(g) What is meant by the term tapping a "blind' hole ?
2.
(20 Marks)
WARNING : Don't forget to return this section with your answer book (if question 2 is attempted) or otherwise marks will be lost.
 

(a) Name and explain any two stages in the design process.

(b) A set of three different size dumbbells (which are weights used to build up arm and shoulder muscles) arc illustrated in the drawing. Design a stand for storing the three dumbbells. Your design may either be :

  1. a wall mounted stand or
  2. a floor stand.

Your design should incorporate a means of holding the dumbbells so that they will not fall off the stand. At least two rough sketches showing your ideas should be drawn in your answerbook.

Select your final design and draw a pictorial view in the grid paper below.

(c) It is important that the surfaces of exercise equipment be in god condition and be easily cleaned. Suggest a suitable finish, other than painting, for such equipment, and explain how your chosen finish is achieved.

                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
3.
(20 Marks)

(a) State two reasons why it is necessary to run drilling machines at different speeds ?

(b) Explain, with the aid of sketches, what is meant by :

  1. A tapping size hole.
  2. A countersunk hole.

(c) A mild steel plate is shown on the right.

  1. Describe, with the aid of a diagram, how you would hold the plate on a drilling machine table while drilling.
  2. List the steps required in order that the holes may be drilled in a correct manner.

(d) The surface cutting speed for the steel in the plate is 25 m/min. Using the given formula, find the correct drilling speed for the 20 mm diameter holes in the plate.

N= (S x 1000) / (π x D
(Take π as 3 for the calculation)

4.
(20 Marks)
(a) Identity the type of furnace shown.

(b) List the three major parts of the charge, and state why each is necessary.

(c) Explain, with reference to M and N in the diagram, how the charge is put into the furnace, without much heat loss.

(d) What is the purpose of the large pipe, C, near the bottom of the furnace ?

(e) Explain the function of the two chutes at A and B.

(f) Study the list of the seven elements in the table. Select elements to make two well known alloys. Name each of the two alloys
ELEMENTS Carbon
Zinc Lead
Chromium Nickel
Copper Iron
5.
(20 Marks)

An illustration of a scrambler type motorcycle is shown. Answer the following questions :-

(a) Name and state materials used in the manufacture of parts A, C and D.

(b) The lever at E operates the brake on the front wheel. Refer to F, G and H, and explain how the brake operates.

(c) The wheel axle, J, has screwthreads for holding the wheel assembly in place. If the screwthread is M16 :

  1. What is the angle at Z?
  2. What is the diameter at Y?
  3. What is diameter X called?

(d) This bike has a chain drive. List two advantages of chain drive over belt drive.

(e) The sprocket at the engine has 18 teeth and the sprocket at the rear wheel has 72 teeth. Calculate the gear ratio.

(f) What effect do the exhaust gases emitted at B, have on the environment?

6.
(20 Marks)

(a) A modern electric soldering iron is shown. From what material is part A made? State one reason why this material is suitable.

(b) Explain, with the aid of a diagram, how the soldering iron tip (Part A) is heated.

(c) This soldering iron is connected to a 24 Volt unit which, in turn, is connected to the electrical mains. Explain why this is necessary.

(d) Some soldering irons are rated 15 W, and some are rated 25 W. Which of these two ratings would be most suitable for soldering small electronic components. Give one reason for your answer.

(e) The mains cable from the 24 Volt unit has three wires: blue, green/yellow, and brown.

  1. State where each wire should be connected in the 13 Amp plug shown in the diagram.
  2. What is the purpose of part M in the plug ?
  3. Explain how the mains cable is prevented from pulling out of the plug.

(f)

  1. Describe three important steps in soldering.
  2. Name the two metals used to make solder.
7.
(20 Marks)

A schematic diagram of a computer system is shown. The CPU is in the centre with the other devices attached to it.

(a) What does CPU stand for, and what is the function of the CPU ?

(b) List any six of the attached devices and state clearly which are input devices, and which are output devices.

(c) Explain any three of the following terms: G-Code, Test Run. CAD, CMC.

(d) Draw a sketch of the jog keys of a CNC lathe, and show the meaning of each of the following:

-x, +x, -z, +z.

(e) State one advantage of a CNC lathe over a conventional machine.