1. | Separators are usually placed between opposing plates in leads acid cells to: A. | prevent the electrodes from touching |
B. | prevent current flow through the cell |
C. | ensure that the positive and negative electrodes are connected |
D. | help with the polarization effect during discharge |
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2. | Gel-type and paste-type electrolytes have become common in lead-acid cells because they: A. | allow the cells to be a larger physical size |
B. | spills and overflow from liquid types |
C. | generate extra voltages to assist the output |
D. | enable the chemical action to dissipate into the plates |
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3. | Look at the following diagram: With reference to the cut-away drawing of a lead-acid cell shown in figure 1, the space at the bottom of the plates is to: A. | ensure that any sludge that form will combine with the plates |
B. | enable the electrolyte to form extra electrodes at the bottom |
C. | prevent any sludge formation from shorting the plates |
D. | prevent the electrolyte form touching the bottom of the plates. |
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4. | Generally speaking, the difference between a primary and secondary cells is that a secondary cell: A. | is smaller for the same output capacity |
B. | will produce alternating current |
C. | has a liquid electrolyte |
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5. | To produce a higher output voltage cells are connected: C. | with their positive terminals together |
D. | so that some are open circuited |
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6. | The number of 1.5 volt cells required to be connected in series to give an output of 9 volts is: |
7. | When two or more strings of cells, or batteries of cells, are connected in parallel in order to increase the available current, they are known as: |
8. | Thirty-six, 2 V, lead–acid cells have been connected in banks of batteries to produce a 24 V supply. The number of banks of batteries will be: |
9. | The ‘nominal voltage’ of a cell is the voltage that the cell should produce with: D. | a small or nominal load connected |
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10. | The output voltage of a cell changes when a current is drown from the cell, due to the voltage drop across the: A. | resistance of the connected load |
B. | internal resistance of the cell |
C. | inductance of the connected load |
D. | ac supply charging the cell |
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11. | The internal resistance of a cell will have a voltage drop across it that adds to the nominal voltage during the charging cycle and: A. | adds to the nominal voltage during the discharge cycle |
B. | assists the nominal voltage during the discharge cycle |
C. | subtracts from the nominal voltage during the discharge cycle |
D. | subtracts from the nominal voltage during the charging cycle |
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12. | Look at the following diagram: With reference to the terminal voltage-drop chart shown in figure 2, if a load current of 40 A is drawn from a 12 V battery with an internal resistance of 0.05 W, then the terminal voltage will be: |
13. | Generally, the energy that a cell can store depends on the type of cell chemically and the: A. | physical size of the plates |
B. | type of positive terminal |
D. | current that the cell can deliver |
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14. | By convention, the energy stored in a cell is measured in: |
15. | The capacity of a lead-acid battery depends on the discharge rate of the battery. A high discharge rate: A. | increases the storage capacity |
B. | will maintain a high storage capacity |
C. | decreases the storage capacity |
D. | improves the output voltage with each charge |
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16. | When mixed ready for use in a lead-acid battery, the specific gravity of the diluted sulphuric acid is: |
17. | Look at the following photo: With reference to figure 3, the picture shows a person carrying out: A. | an electrolyte specific gravity test on a battery |
B. | a voltage test on a car battery |
C. | a current load test on a battery using a dummy load |
D. | an electrolyte voltage availability battery test |
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18. | The state of charge of a battery can often be determined from the: B. | condition of the electrolyte |
C. | date code on the battery |
D. | no-load current level of the cells |
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19. | One type of battery that is rapidly degraded by excessive and repetitive deep discharges is: A. | a stand-alone power supply battery |
B. | a rechargeable battery for a power tool |
D. | a battery for an electric vehicle |
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20. | Look at the following table: With reference to the specific energy table shown in figure 4, the type of cell with the highest energy per kilogram is: A. | sealed zinc-mercury cell |
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21. | In automotive terms, the maximum current expected from a battery is called the: C. | continuous cranking amps |
D. | crankcase consolidated alternator |
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22. | The efficiency of a battery can be determined using the formula, percentage efficiency = |
23. | The cycle-life of a battery is the number of times they can be: A. | used on an electric bicycle |
B. | recycled when no longer serviceable |
C. | discharged and recharged |
D. | used before damaging a battery power tool |
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24. | Some of the dangers that must not be ignored for when working with cells and batteries are: D. | all of the given answers |
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25. | While charging, batteries can vent off a gas such as: |
26. | Lead-acid batteries and alkaline batteries should be kept separated, as the mixing of acids and alkaline can lead to: B. | very volatile chemical reactions |
C. | increased output capacity in some types |
D. | decreased output voltage level in alkaline cells |
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27. | One maintenance procedure with wet cells is to regularly check the electrolyte level because if they are not kept covered they will: A. | produce excessive voltage |
B. | increase the cell capacity |
D. | consume the electrolyte |
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28. | Cells that are getting old typically have: A. | a higher output voltage |
B. | a lower internal resistance |
C. | larger amount of electrolyte |
D. | an increasing internal resistance |
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29. | The electrolyte in the zinc-alkaline cell is B. | amalgamated zinc granules |
C. | compacted manganese dioxide |
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30. | In the zinc-mercury type of cell, the negative electrode is made from: A. | of potassium hydroxide |
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31. | When compared with other types, the lithium cell’s output voltage tends to: A. | increase at a slow rate over the cell’s lifecycle |
B. | decrease at a rapid rate over the cell’s lifecycle |
C. | remain more constant over the cell’s lifecycle |
D. | become unstable at different times over the cell’s lifecycle |
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32. | When compared with other types of cell of comparable size and weight, lead-acid cells can deliver: A. | higher voltages for longer times |
B. | only about half the current of the others |
C. | full current for prolonged periods of time |
D. | higher current for short bursts |
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33. | As the active materials of a lead-acid cell have no rigid mechanical form or strength they are mounted in a lead grid. The grid usually has antimony added to the lead: A. | for rigidity and extra mechanical strength |
B. | to help keep the internal resistance low |
C. | to increase the out capacity of the cell |
D. | in order to prevent polarisation during charging |
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34. | During the discharge cycle of a lead-acid cell, the sulphuric acid electrolyte ionises in the water to form positive hydrogen ions and: A. | positive sulphur-dioxide ions |
B. | negative sulphate ions |
C. | positive sulphate ions |
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35. | Once a lead-acid cell is fully charged, the hydrogen and oxygen, being liberated cannot combine within the cell and: A. | will now combine outside the cell |
B. | regenerate into the positive and negative electrodes |
C. | vent to the atmosphere as gas |
D. | assist with the depolarisation effect |
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36. | For successful operation, the sealed lead-acid cell must be charged at a rate that will: A. | cause the gas to build up a good pressure within the cell |
B. | ensure that the gas pressure within the cell does not fall below the set level |
C. | enable the voltage on the plates to undergo a transfer characteristic effect |
D. | not cause any gas to build up excessive pressure within the cell |
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37. | One advantage of the lead-acid cell with a gel electrolyte is that they can be used: B. | when completely discharged |
C. | for a longer period on high currents |
D. | when an ac supply is required |
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38. | There are two major types of nickel-alkaline cells. One has nickel-iron electrodes and the other has: A. | nickel-lead electrodes |
B. | nickel-cadmium electrodes |
D. | pure alkaline electrodes |
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39. | One advantage of the nickel-metal hydride cell secondary cell is that it: A. | has a limited shelf life |
B. | does not maintain a high output voltage during discharge |
C. | is capable of many charge/recharge cycles |
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40. | The modern fuel cell gives more energy per unit mass than a storage battery and in addition: A. | the electrodes of platinum black undergo a chemical change |
B. | has the same output voltage as a lead-acid cell |
C. | is very inexpensive to manufacture |
D. | water is produced as a useful by product |
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41. | The main requirements for batteries for standby power supplies are they must have a long life with a low self-discharge rate and: A. | lose a minimum of electrolyte over long periods |
B. | generate a good volume of hydrogen during charging |
C. | be able to be used in any position |
D. | have a robust construction so they can be frequently moved |
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