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35 Cards in this Set
- Front
- Back
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What is the purpose of a cell?
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A cell is a device that converts chemical energy to electrical energy.
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What are the three parts of a cell?
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The electrodes, the electrolyte, and the container.
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What is the purpose of each of the three parts of a cell?
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The electrodes are the current conductors of the cell. The electrolyte is the solution that acts upon
the electrodes. The container holds the electrolyte and provides a means of mounting the electrodes. |
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What are the two types of cells?
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Primary and secondary.
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What is the main difference between the two types of cells?
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The secondary cell can be restored to its original condition by an electric current. The primary cell
cannot. |
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What is electrochemical action?
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The process of converting chemical energy into electrical energy.
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What is another name for the (a) positive electrode, and the (b) negative electrode?
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(a) The anode, (b) the cathode.
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In the primary cell, why are negative ions attracted to the negative terminal of the cell?
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The positive charge caused by electrons leaving the negative electrode attracts the negative ions.
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How do electrons get from the negative electrode to the positive electrode?
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By current flow through the load.
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What causes the negative electrode to be eaten away?
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The chemical action between the negative electrode and the electrolyte.
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Describe three ways to prevent polarization.
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Vent the cell, add a material rich in oxygen, and use a material that will absorb hydrogen.
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Describe local action
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Current flow in a cell with no external load.
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What serves as the cathode of a dry cell?
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The zinc container.
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Why is a dry cell called a DRY cell?
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The electrolyte is not a liquid but is in the form of a paste.
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What does the term "shelf life" mean?
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The period that a cell can be stored and still be useable.
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Why should a mercury cell NOT be shorted?
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The danger of explosion.
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What factors should be considered when selecting a primary cell for a power source?
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Cost, size, ease of replacement, and voltage or current needs.
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What are the four basic types of secondary (wet) cells?
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Lead-acid, nickel-cadmium (NICAD), silver-zinc, and silver-cadmium.
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What are the advantages of a nicad cell over a lead-acid cell?
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Can be charged in a shorter time, can deliver a larger amount of power, and stays idle longer.
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What type of cell is most commonly used for emergency systems?
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Silver-zinc cell.
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What three cells use the same electrolyte?
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Silver-cadmium, silver-zinc, and nickel-cadmium.
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What does the term battery normally refer to?
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A voltage source in a single container made from one or more cells.
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What are the three ways of combining cells, and what is each used for?
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Series, to increase voltage but not current. Parallel, to increase current but not voltage. Series-
Parallel, to increase both current and voltage. |
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Other than the type of cell used, what is the major difference between the construction of the leadacid
and nicad battery? |
The cells in the nicad battery can be replaced.
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How is the type of battery most easily determined?
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By looking at the nameplate data.
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What is the purpose of the hydrometer?
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To measure the amount of active ingredient in the electrolyte.
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Which electrolyte has more active ingredient? Electrolyte A, specific gravity 1.015? Electrolyte B,
specific gravity 1.125? |
Electrolyte B. It is heavier per unit volume.
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When should safety precautions pertaining to batteries be observed?
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At all times.
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How long should a 200 ampere-hour battery be able to deliver 5 amperes?
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Forty hours.
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Can a battery be recharged by adding more electrolyte?
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No, a current must be passed through the battery.
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If violent gassing occurs during a battery charge, what action should be taken?
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Reduce the charging rate.
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types of charges may be given to a storage battery, depending upon the condition of
the battery: |
1. Initial charge
2. Normal charge 3. Equalizing charge 4. Floating charge 5. Fast charge |
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Provide a higher voltage than a single cell, with no increase in
current. |
SERIES CONNECTED CELLS
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Provide a higher current than a single cell, with no increase in
voltage. |
PARALLEL CONNECTED CELLS
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Provide a higher voltage and a higher current than a
single cell. |
SERIES-PARALLEL CONNECTED CELLS
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