Engineering - Exam Papers - OL - Paper - 1993
200 Marks
Answer Question 1, Sections A and B and THREE other questions.
Section A - 30 Marks
Give brief answers to any six of the following :
| (a) |
State two safety precautions
related to the use of a CNC Lathe. |
| (b) |
Name a common semiconductor. |
| (c) |
Sate two methods of
self-locking nuts and bolts. |
| (d) |
Give a typical application of
vacuum forming. |
| (e) |
State three methods of
protecting steel sheet from rusting. |
| (f) |
What is the function of a diode? |
| (g) |
What is galena? |
| (h) |
State two safeguards
necessary when using adhesives. |
Section B - 35 Marks
Answer any three of the following :
| (i) |
Describe the construction and use of a ratchet and
pawl mechanism. |
| (j) |
Explain two of the computing
terms : bit, RAM, hard disk, software. |
| (k) |
Identify three types of
electronic circuit board. |
| (l) |
Explain any two of
the terms : thermostat, capacitor, rack and
pinion, plotter, reamer. |
| (m) |
Name the components A, B and C shown
in the pneumatic circuit and explain the function
of the component marked X. |
|
| (a) |
Describe, with the aid of a
diagram, the production of steel and explain the
terms: |
| (i) |
tapping and |
| (ii) |
slagging. |
| (b) |
What is alloy steel?
Identify two types of alloy steel and
state their properties. |
| (c) |
Give two properties and two
applications of: |
| (i) |
aluminium; |
| (ii) |
bronze; |
| (iii) |
lead. |
| (a) |
State two differences
between oil and water for quenching during heat
treatment. |
| (b) |
Describe the different heat
treatments applied to a cold chisel. |
| (c) |
Explain the terms: |
| (i) |
normalising; |
| (ii) |
case-hardening. |
| (a) |
With regard to oxy-acetylene
welding: |
| (i) |
name three types of flame; |
| (ii) |
state the circumstances in which
each flame is used; |
| (iii) |
discuss, briefly, the proportions
of oxygen and acetylene in each of the flames
mentioned. |
| (b) |
The essential features of
electric welding are shown in the diagram. |
| (i) |
What is the name of the device
represented by A? |
| (ii) |
Name the coils B and C and state
their function. |
| (iii) |
Name part D and state its
function. |
|
| (c) |
Why is a flux-coated electrode used
in electric arc welding? |
OR |
| (c) |
Identify two types of
sensor used in robotic welding. |
| (a) |
Name two thermosetting
plastics and state a typical application of
each. |
| (b) |
List two safety
precautions to be observed when using plastic
dip-coating equipment. |
| (c) |
Describe the blow moulding
process with the aid of a sketch. Discuss: |
| (i) |
the type of plastic used; |
| (ii) |
the equipment; |
| (iii) |
the methods of heating and
cooling; |
| (iv) |
a typical application. |
| (a) |
What advantages relate to the use
of a cutting fluid when machining? |
| (b) |
Explain the following with regard
to machining: |
| (i) |
mandrel; |
| (ii) |
faceplate; |
| (iii) |
surfacing. |
| (c) |
Sketch a cutting tool showing the
following features: |
| (i) |
top rake; |
| (ii) |
front clearance; |
| (iii) |
side clearance. |
OR |
| (c) |
Explain the following terms
associated with the CNC lathe: |
| (i) |
stepper motor; |
| (ii) |
G-codes; |
| (iii) |
canned cycle. |
| (a) |
Give an example of |
| (i) |
a bilateral
and |
| (ii) |
a unilateral tolerance. |
| (b) |
Sketch two types of limit
gauge and explain the function of each. |
| (c) |
Describe each of the following: |
| (i) |
dial gauge; |
| (ii) |
feeler gauge; |
| (iii) |
thread gauge. |
OR |
| (c) |
Explain the following
terms: |
| (i) |
digital readout; |
| (ii) |
liquid crystal display
(LCD); |
| (iii) |
light-emitting diode (LED). |
