Auto mechanics Paper 2 WASSCE (SC), 2020

Question 2

 

(a)  (i) What is the difference between wheel and wheel rim?
(ii)  List two types of wheel; wheel rim.
(b)  What instrument is appropriate for checking tyre pressure?
(c) An automobile tyre has the mark, 195/60/R15, written on its outer surface. Explain, as applied to the mark, what the following indicate;
   (i) 195;            (ii) 60;             (iii)       R15


Observation

 


Candidates’ responses to questions on wheel and wheel rim were not adequate. However, they were able to mention the instrument for checking tyre pressure. Responses to 2(c) were not also satisfactory. The solutions to the poorly answered part of the question are given below


(a)  (i) The wheel consists of a rim and a disc while Wheel rim is the metallic part of a wheel on which the tyre is fitted.
            Types of
                        (ii) Wheel
- Steel pressed wheel or pressed steel wheel
                                    - Wire or spoke wheel
                                    -Alloy based wheel or alloy wheel
                                    Wheel rim
- Safety rim or one-piece wheel rim
- 2-piece rim or wheel rim
- Divided or split rim or wheel rim
- Semi-drop-centre rim or wheel rim
- 3-piece rim, 3-piece wheel rim or multi-part wheel rim.

 (c)  (i) 195: It indicates the sectioned width of the tyre
(ii)  60: Indicates the sectional height (60% of the width)
(iii)  RI5: R means radial ply and the15 means rim diameter in inches