Please note that connecting batteries in series does add up their respective voltage outputs. That is to say two 9-volt batteries connected in series will give 2 X 9 = 18 volts.
On the other hand, connecting batteries in parallel does NOT change their total voltage output. Any number of 9-volt batteries connected in parallel will give a total voltage output of 9-volts.
I have NO idea about the term (مركبة) but (على التضاعف) is obviously connected in series.


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Note added at 2004-12-17 21:08:50 (GMT)
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Capacity does NOT increase when you connect two similar batteries in parallel. Please check the following links:
http://ourworld.compuserve.com/homepages/g_knott/elect27.htm & http://www.batteryuniversity.com/partone-24.htm


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Note added at 2004-12-19 19:22:15 (GMT)
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Based on your new note, “التضاعف” means in parallel which is the setup where the amperage increases.
For overall clarity, parallel connection of batteries does NOT increase voltage but it increases the amperage.
On the other side, series connection of batteries increases voltage but it does NOT increases amperage.

Arabic term (edited): �������

to make the voltage twice higher

Arabic term (edited): �������

I'm no expert in electronics, but from some searches I did on Google, I think that's it.

he five mini bulbs can be quickly arranged in series, parallel,
or complex circuits, simply by adjusting the Buss bars. 5 bulbs included. ...
www.arborsci.com/Products_Pages/ Electricity/ElectricityBuy1.htm

Complex circuits are a combination of resistors in parallel
and in series. steps in simplifying complex circuits ...
www.cyberclassrooms.net/~pschweiger/dccircuits.html

Your team will construct an electric house with separate series, parallel, and complex circuits. The house will consist of two ...
cpphysics.homestead.com/house.html