Observation

           The expected answers were;

 

1. (b)Function of vents in a motor vehicle battery
2. To release the gases produced during charging or discharging.
3. To prevent built up gases in the battery casing.

• (c)
• (i)Effect of decreased electrolyte level in the operation of a battery
• Rapid loss of water leading to increased acid concentration;
• Irreversible sulphation;
• Damage of cell;
• Longer charging time due to decrease in cell capacity and time;
• Frequent discharge of the batteries.
• (ii)Effect of terminal sulphation in the operation of a battery
• Oxidation leading to circuit breakdown
• Increase resistance in the flow of electricity from the terminals to the cable;
• Premature replacement of battery;
• Corrosion of battery post;
• Corrosion of battery terminal.

The candidates were required to draw wet cell and dry cell and label any two parts of each. In     handling this question, it is clear that majority of the candidates do not know how the cells look like as it is evident that they drew well those items known to them.