This question was one of the most difficult question for the candidates.  Parts (a), (b) and (c) were extremely difficult for the candidates.  The required responses to these parts are:

(ai)       The purpose of investigation in design is to provide the designer with required information about the design specification.

(aii)      Methods of carrying out investigation are:

-           observation;
-           interview;
-           literature review;
-           experiment;
-           questionnaire.

(b)        The difference between passive flux and active flux is that passive flux only protects the cleaned surface while active flux cleans and protects the surface.
(c)        (i)         Examples of passive flux are:
-           resin;
-           tallow.

(c)        (ii)        Examples of active flux are:
            -           Hydrochloric acid;
-           zinc chloride;
-           sal ammoniac.