Correct Answer - Option 1 : Fully charged
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The electrolyte in a lead-acid cell is dilute sulphuric acid (H2SO4) solution mixed in such a proportion so that with a fully charged battery, its specific gravity is about 1.28
- Dilute sulphuric acid is used as electrolyte by adding Sulphuric acid to water
- Spongy lead is used for negative plate
- Lead peroxide paste is used for positive plates
- It has low internal resistance
- It requires more charging time
- Gases are evolved during charging
- During the normal life of a battery that is properly cared for, the electrolyte loses none of the acids
- During the charging process, the specific gravity of the electrolyte (H2SO4) increases and provides an important indication of the state of charge of the cell
- The specific gravity of the electrolyte of a fully charged lead-acid cell is about 1.28; This can be measured by means of a hydrometer
In practice, the state of charge of a lead-acid cell (or battery) is determined from the specific gravity of the electrolyte. The following table is useful in this regard.
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The specific gravity of H2SO4
|
State of charge
|
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1.13
|
Discharged
|
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1.19
|
25% charged
|
|
1.22
|
50% charged
|
|
1.25
|
75% charged
|
|
1.28
|
100% charged
|
Explanation:
As in the option, 75% charged not given so the most appropriate answer is fully charged.
