Hi there!
It's my first post here, but let me put my hand here!
The thing is actually a lot simpler than stated here in previous posts.
A battery does not produce anything! It just delivers energy that is stored in it in chemical form according to some demand. Demand here means a load that is connected across the battery terminals.
If we have a 40Ah 12V battery then it will deliver 12 V into a load at a current that depends on the load itself. If the load is 1 ohm then the current will be 12A. The battery will be able to supply this current for over 3 hours. It will supply 40A during one hour, 20A into 2 hours and so on. If the battery is subject to a short circuit then it will supply a very large current during a very short time if it isn’t damaged. In reality, the battery has some internal resistance which will cause the output voltage to drop and therefore the current will drop as well.
If 2 batteries are connected in parallel, then the current capacity is summed and the voltage remains the same. There are only 2 terminals in this configuration anyway. So 2 12V 40Ah batteries in parallel are equivalent to one 12V 80Ah battery.
If two batteries are connected in series, the result is a battery with a voltage that is the sum of the individual voltages and the current capacity remains the same. This is very similar to the 2 1.5V batteries that are used in some light torches in order to get 3V.
Going back to the original questions, I think that in my opinion, the wording is not the best. But answer A is the best one! For the series connection of batteries, the answer to tolipanebas ´s question should be C.
Hope this was clear!!!
