Iqra,
Ammeters are used to measure the current (or the electrons) going
through something. In order to do this they are hooked up in series,
with what you're measuring. Let's say that you want to measure the
current through a resistor. In order to do that you would remove the
wire from one of the ends of the resistor, place it into an ammeter and
then run another wire from the ammeter to the resistor. For instance,
if you had a pipe, and you wanted to measure the water flowing through
it, you would have to hook up something to measure it that had the same
amount of water flowing through it as the pipe. Therefore, you could
replace a section of the pipe with your measuring device. If you think
of the water as current, this is how ammeters work.
Voltmeters are a little different. They measure the voltage across
something. (This is known as the potential difference.) In order to
measure voltage you need two points so if you wanted to measure voltage
in this case, you would add a wire from each side of the resistor to
the voltmeter. The voltmeter would then tell you the difference in
voltage between one side of the resistor and the other.
Basically, the reason that ammeters and voltmeters are connected
differently in circuits is because of the differences between current
and voltage.
~Ann
(published on 10/22/2007)
