Fly Lah!

Which is the correct answer?

When a lead acid battery is charging,
a. current flows into the battery and causes sulphuric acid to flow back to the electrolyte
b. current flows out of the battery and causes lead sulphate to form on both plates
c. current flows into the battery and causes lead peroxide to form on both plates
d. current flows out of the battery and sulphuric acid is removed from the electrolyte

None of the above?
I don't see any answers there.

I am waiting for sombody to answer.

Let's do some elimination process.
When charging the lead acid battery, current is going INTO the battery, so we can remove answers b. and d.

The battery plates when discharged are covered with lead sulphate (which is actually lead + sulphuric acid), during charging they are converted back to Lead and Sulphuric acid is released back into the electrolyte (putting the acid back) Hence the best answer is a.

Also during charging current passing through the electrolyte and water will convert the water into it's elements, H2 and O which is released as gas into the atmosphere making the electrolyte more 'concentrated' ie 'loss of quantity/volume' that necessitates the usage of battery water/distilled water to be used to top up the level.