Please clearify my thoughts.

[holax12]

Hello,

If i connect a load in series with an ampere meter , the load has its own resistance thus , resist the flow of current.
Now on the amps meter a reading is displayed. Is it the current flowing through the load that is been displayed? or the current used up by the load?

 

[KeepItSimpleStupid]

MOST ammeters have an internal resistance, thus the new load would be the sum of the old load and the ammeter assuming a resistive load. If that load had a voltage dependence, it would be more difficult to determine.

What IS true is that the ammeter is measuring the current though the old load which may have a voltage or current dependence and the internal resistance of the ammeter.

Where this can come an bite you is if you have a solar cell which has a Vmp on the order of 0.6 volts and Imp on the order of 10 mA and you insert an ammeter having a resistance of 10 ohms you'll have serious errors if you assumed the same voltage that you had before the insertion.

The rotten part is cheap DVM's don't tell you the maximum voltage burden at full scale or the internal resistance.

Current is Coulombs/sec and a couloumb is a unit of charge. The charge on an electron is aproximately 1.602176487(40)×E−19 coulombs. So, to answer your question it' is measuring the same flow flowing through each, not the sum. Conventional current is defined as going from the positive terminal to the negative terminal, BUT the electrons are going the other way. In semiconductor physics where it matters, this positive to negative conventional current flow is known as hole flow.

I probably confused you and I only touched on the subject.

One of the intuitive analogies is to think of current as water flow, voltage as water pressure and resistance as the internal diameter of the pipe.

 

[audioguru]

I think most DMMs have a full scale voltage drop of 0.2V which is a voltage loss. So the load current is reduced a little by this voltage loss.

The current flowing through the load is exactly the same current that is used up by the load so it is the same number of amps.

 

[KeepItSimpleStupid]

Don't assume anything: See page 45: https://www.electro-tech-online.com/custompdfs/2010/12/8xiii___umeng0500.pdf.

Voltage burden depends on range.

Current is never USED UP, Current FLOWS. Please provide a refererence. Kirchoff's voltage law would not be valid. This states that the sum of the I*R drops in a curcuit is equal to zero. The current (I) flows through all of the elements.

 

[holax12]

thanks for your replies, but i dont seem to be getting it.
For example , a load has a current consumption of 100mA. If i connect an amps meter in series with the load and a 100ma source , is it still the 100ma that will be displayed or the 100ma would hav been used by the load and the meter just display zero amps flowing through.

 

[KeepItSimpleStupid]

Current is NOT CONSUMED. End of story. Never would read zero under the conditions you descibed.

There is a particular current meter called a clamp-on ammeter, that you can put it's jaws around a wire or even a resistor or multiple resistors in series (connected end to end). Everywhere you put that contactless ammeter, it would read the same current even if it it's jaws were encircling of any of the resistors.

OK, is the source a CURRENT source or a VOLTAGE source? There is a BIG difference. An IDEAL voltage source has an internal resistance of zero. An IDEAL current source has an infinate internal resistance.

A battery is a Voltage source. The AC wall outlet is a voltage source. Constant current sources are less common. A good use for a constant current source is in charging a battery.

 

[vlad777]

thanks for your replies, but i dont seem to be getting it.
For example , a load has a current consumption of 100mA. If i connect an amps meter in series with the load and a 100ma source , is it still the 100ma that will be displayed or the 100ma would hav been used by the load and the meter just display zero amps flowing through.

If components are in series trough all of them flows the same current, but voltage is divided between them.
if components are in parallel there is same voltage on them but current is divided between them.

So in your case if you have load in series with ampere meter same current will flow through both,
and meter will show current that flows through load and this current also flows trough ampere meter.

 

[tiffanyscalen]

ya the current flowing thought the load is been displayed but that best answer of this question is stay on our sites.