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Question 3
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Question 3
Remove the filler caps from the battery cells and do the following:
(a) copy Table 1 into your answer booklet;
Table 1
Cell |
1 |
2 |
3 |
4 |
5 |
6 |
Specific gravity |
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Temperature (0C) |
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Condition of cell |
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(b) squeeze the hydrometer bulb and insert the pick-up tube into the cell closest to the
positive terminal of the battery (cell 1);
(c) slowly release the bulb to draw in electrolyte to cause the rising of the float;
(d) read and record in Table 1, the specific gravity and temperature of the cell;
(e) repeat steps (b) to (d) for the remaining five cells (cells 2 to 6);
(f) using the readings obtained in Table 1, determine the state of charge of each cell.
NOTE: (i) Write good if ok.
(ii) Write bad if cell is damaged. |
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The expected answers were:
(a) Table 1
Cell |
1 - 6 |
1 – 6 |
Specific gravity |
1.19 – 1.29 |
Below 1.19 |
Temperature (0C) |
250C – 600C |
Above 600C |
Condition of cell |
Good |
Bad |
State of cell |
Ok |
Damaged |
Note: The reading of the specific gravity of a particular cell determines the temperature, condition of cell and state of the cell.
As reported, the candidates of the only examination centre that attempted this question performed fairly well.
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