Observation

  This is the most popular question. Majority of the candidates responded to it. It was reported that the performance of the candidates in the question was good.
 
   In part (a), Majority of the candidates had good knowledge of first-aid. 
  In part  (b), majority of the candidates had good understanding of illumination, and they were able to list three types of lamps used for street lighting.
  In part (c), majority of the candidates defined cable. 
  In part (d), majority of the candidates stated two methods of joining electrical conductors.

The expected answers are:

3.(a)(i)    First-aid is a temporary treatment given to an accident victim before a professional
Arrives.                                                                                                                               

                      OR
First-aid is the treatment given to an accident victim before taken him/her to the hospital.

    (ii)    Procedure of administering artificial respiration
-   clean the victim’s mouth to remove any particle/foreign material
-   position the victim on the floor with the head tilted backward
-   take a deep breath
-   place your mouth on the victim’s mouth
-   blow air into victim’s lungs/mouth/nostrils until chest expands
-   repeat the process several times until the victim starts breathing/
professional arrives.                                                                                  

   (b)(i)  Maintenance factor
This is a loss in light output due to lamp ageing and dirt on the lamps/fittings.
 
(ii)   Lamps used for street lighting
-     high pressure mercury vapour lamp
-     sodium discharge lamp
-     LED light
-     high intensity discharge lamp                                          

  (c)(i)    A cable is defined as a length of insulated conductors OR A cable is defined
as two or more conductors each provided with its own insulation.
 
(ii)  Types of cable based on their constructional features     
-      polyvinyl chloride  (PVC)
-     lead sheathed
-     vulcanized India-rubber insulated (V.R.I)                  
-     tough-rubber-sheathed (T.R.S)
-     mineral insulated/MICC/MISC
-     polychloroprene (P.C.P. or neoprene)
-     paper insulated lead-covered
-     heat resisting, oil-resisting and flame-retardant (H.O.F.R)     
-     armoured cable                                                                                                         

(iii)   How current rating of a cable is affected by ambient temperature
As temperature increases, the surrounding air increases , the resistance of
the cable Increases hence the current rating of the cable decreases  vice versa.                                                                                                                                                                        
(d)  (i)   Methods of joining electrical conductors
-   mechanical method
-   soldering method
-   welding method                                                                                                       

    (ii) - Mechanical method - This is done by using connector blocks/bolt and nut . It is a   
manual way of joining.   

          - Soldering method-   This is the process of joining conductors using heat/soldering
bits.
-  Welding method- This involves the use of flames from gas in joining conductors.