Metal Works 2, WASSCE (PC), 2017

Question 3

 

(a)        State two effects of fumes in the workshop.
(b)        State two design questions which serve as guides when evaluating a finished product.
(c)        State one reasoneach for using the following materials in making the respective items:

(i)brass for water taps;

(ii)aluminium for overhead electricity cables;

(iii)copper for soldering iron.

(d)       State one mechanical property of ferrous metals.

Observation

 

Part (b) of this question seemed to pose some difficulty to the candidates as many were not able to answer it correctly. The required responses are as follows:
           

3(a)      Effects of fumes in the workshop

  • Inhalation of fumes causes respiratory disorders.
  • Exposure to fumes can cause skin irritation.
  • It causes poor visibility in the workshop.
  • It affects the eye.

(b)        Two design questions which serve as guide when evaluating finished product

  • How well does the product function?
  • Does it meet the needs of the user?
  • Does the product look good?
  • Is the product safe to use?
  • Can the product be maintained easily?
  • Is the product durable?

(c)        Reason for using the following materials in making the specified items:

  • brass for water taps
  • it is non-poisonous.
  • It does not rust.
  • It does not corrode.
  • aluminium for overhead electricity cables
  • It is light in weight.
  • It is a good conductor of electricity.
  • It is a good conductor of heat.
  • It is readily available.
  • copper for soldering iron
  • It is a good conductor of heat.
  • It is a good conductor of electricity.
  • It can retain heat for a long time.

 

(d)       Mechanical properties of ferrous metals

  • Hardness
  • Ductility
  • Brittleness
  • Toughness
  • Malleability
  • Tenacity
  • Elasticity