ammeter

Somebody please correct me if I am wrong. When measuring amperage the meter is connected in series with the circuit being measured. Voltage is measured in parrelell.

I don't quite understand your question.

Ammeters are connected in series with the load, this is because in series, the current is constant througout all loads in the circuit.

Voltmeters are connected in parallel with the load or device which needs to be measured, as voltages remain constant for loads in parallel.

Is it "Kirchoff's Law" or something else?

No no no no . . . not the 'K' word again. Here we go Andy !

To use the good old water analogy.

A river flowing down a mountain side.

The current is the flow of water so to measure it, the water has to flow through the measuring chanel. The Voltage is the height between the top and bottom of the maountain..e.g. the potential energy.... measured between two points.

Priyanka, If i understood your question, you are asking why ammeter ( Moving coil/iron) is connected Bat ( +) ===> Ammeter (+) ===> Ammeter (-) ===> Load===> Bat (-) and not to (-) of ammeter. This is done to to get the deflection in the ammeter in clockwise direction, if you connect to negative the needle will move towards the zero side of the meter and bang against the stopper. The positive is marked at the terminals so as to avoid damage( mechanical) to the ammeter if connected wrongly. Hope you are satisfied..with the answer. Chaterpilar

Dear Priyanka,

I agreed with chaterpilar answer you are puting your batteries on wrong direction,but now in market amp meters are availabel if you put battery in wrong direction its dos,nt work.SIDDIQUI

It might help to know that, in the old days, all meters were constructed using moving coil galvanometers, where the current passing through the coil produced a torque that deflected a needle.

To make a voltmeter, one put a high resistance in series with the meter.

To make an ammeter, one put a low resistance in parallel with the meter.

But, both meter movements were really the same and so their polarity should be the same. The convention remains today.

If you have an application where current can flow either way, the ampmeter must be connected properly or it will apperar that the current is flowing backwards. In a car the load is connected to the aleternator and the ampmeter is connected between the load/ alternator and the battery. If the alternator is putting out enough to supply the load and some extra, the ampmeter will swing positive to show that the extra current is charging the battery. If the alternator output is low or the load high, it will show current coming from the battery to the load, eventually resulting in a dead battery. If the ampmeter is connected backwards, the indication would be backwards. -- JHF

The old ammeters had a zero in the middle, and a negative and positive scale. As another person points out, if the alternator is 'charging' properly, the needle moves to the positive direction as the alternator is creating flow of current sufficient to supply the auto circuits plus charge the battery. If the alternator is kaput, or turning very slowly, the battery is supplying the load for the auto circuits as the alternator doesn't have enough energy to feed the auto AND charge the battery.

To use brother Del's analogy of water, amps is flow, voltage is pressure and connecting it properly means the direction of water flow of the instrument matches your cultural understanding of which way water is flowing (current flow direction, so to say). If you connect the ammeter backwards, it is like connecting a water flow meter backwards and instead of reading "the pump [alternator] is filling up the tank [battery]" it will fool you and read, the "tank is filling up the pump" which is not true unless the pump (alternator) is really kaput.