Question 3
(a)        State two safety precautions to be observed on each of the following:
                        (i)        checking the specific gravity of an  electrolyte;
                        (ii)        jacking a vehicle;
                        (iii)       working on an overheated water-cooled  engine.
            (b)        (i)         What equipment is used to put out fire  in an engine?
      (ii)        Name the constituent of air that  supports combustion.
Observation
Most of the candidates who attempted this question perform poorly as they could not provide the required responses to the various parts of the question. The required responses to the various parts of the question are:
(a)  (i)  Safety precaution when checking the specific  gravity of electrolyte are:
      -           wear rubber apron or wear protective  dress;
      -           put on rubber hand gloves or put on  hand gloves; 
      -           keep naked flame away from the  battery;
      -           keep the top of the battery dry;
      -           avoid spilling of the electrolyte on  the battery;
      -           keep the hydrometer vertically when taking the reading.
    
(ii)        Safety precautions  when jacking a vehicle are:
      -           ensure vehicle is on a level ground;
      -           ensure appropriate jack is used;
      -           use a jack in good working condition;
      -           use wedges to chock the un-raised  tyres;    
- place the jack at appropriate point;
-           support the vehicle with an axle  stand at the appropriate point or do not work under a vehicle which is not  supported on an axle stand.
      
      (iii)       Safety precautions  when working on an overheated water-cooled engine are:
      -           switch off the engine;
      -           open the bonnet;
      -           allow the engine to cool down for a few minutes;
      -           turn the cap briefly to release the pressure in the  system;
      -           allow the engine to cool down properly before refilling  the radiator;
      -            never pour cold water into the radiator of a hot  engine.   
(b)        (i)         Fire extinguisher
      (ii)        Oxygen0
