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