2000ma is equal to 2 amps. Set you meter to a current range ABOVE 2 amps.
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Two ways to connect an ammeter, You can use a direct reading type, by connecting the ammeter in series with the load. You can use a current transformer type or CT. The current transformer looks like a wire wrapped donut with two terminals on its side with a hole through the middle. you pass the wire carrying the load through the center. Connect the direct reading meter to the two terminals. A CT type meter allows you to measure higher currents.
The voltmeter is connected parallel to the circuit in order to measure the voltage drop across that circuit or sub-circuit. If you were to connect the volmeter series to the circuit, since it is a high impedance device, it would represent an effective open-circuit condition. You would see the voltage available to the circuit, but the circuit would not receive its intended current and it would not function. Contrast this with the ammeter, which you do place series to the circuit in order to measure the current flow through the circuit.
You are probably referring to a 'polarity mark'. This is very important if the CT's burden requires current to flow through it in a particular direction in order to work properly. For example, it won't make any difference if the burden's an ammeter. But if the burden is, say, a wattmeter, then it's very important to observe the CT's polarity mark when it is wired, otherwise the wattmeter might read 'downscale' (backwards). It's also very important when the CT supplies protection relays.
heat
Ohms law
An ammeter is placed in series with a circuit in order to measure the current. If it has any appreciable resistance, inserting the ammeter will increase the normal resistance of the circuit and reduce the value of the current flowing through it. The ammeter will, therefore, give an inaccurate reading (under-read). So the ammeter must have a very low resistance so that it has the minimum effect on the normal resistance of the circuit being tested. Ideally, the ammeter should have zero resistance but, of course, this is impossible.
aryton shunt in a multirange ammeter is basically a bunch of resistors(shunt) connected together in parallel to the Dc ammeter and a selector switch in order to basically extend the range of the current...
I am going to assume that you mean low "resistance" in an open circuit test and are performing this with a multimeter. An ammeter works by place a very small amount of resistance in series with a circuit and then measuring the Voltage drop across the resistance. The Voltage is directly proportional to the current as given in ohms law: E = I x R If you are measuring the resistance through the ammeter it will have a very low resistance and impedance.
calibration of an ammeter is done in order to standardise the instrument,and rectify the errors present in the instrument, if any.
You don't. ...unless you want to directly measure the current in a circuit branch. That's the purpose of an ammeter. You can also use a volt meter if you know the resistance of a resistor in that branch to determine current (assuming DC circuit here) - current = voltage / resistance. This may be more useful for circuitry that is on a breadboard, since inserting an ammeter may not be practical.
A current transformer works on the same principle as that of a simple transformer however it steps down the high current into a low level so that it can be measured using an ammeter of a suitable range. In some current transformers extra cores are provided. This is done in order to prevent the faulty currents i.e. the over currents, earth faults, differential protections. The extra cores of a C.T. gets saturated as soon as the faulty currents starts flowing and thereby does not harm the main core of the transformer and the ammeter connected. The C.T. is always connected in the line carrying current. It first steps down the current to a measureable form and further gives this current to the ammeter.
Since Galvanometer is a very sensitive instrument therefore it can't measure heavy currents. In order to convert a Galvanometer into an Ammeter, a very low resistance known as "shunt" resistance is connected in parallel to Galvanometer. Value of shunt is so adjusted that most of the current passes through the shunt. In this way a Galvanometer is converted into Ammeter and can measure heavy currents without fully deflected.
Because if high resistance is like kilo mega ohm is used , corresponding current through the balanced point is in the order of micro ampere, so you have to use micro ampere sensitive ammeter , otherwise normal ammeter always show zero reading
In series with the circuit and never in parallel. The reason being that it will cause the circuit total resistance to drop which will make the circuit draw excessive current. That's a short circuit actually.
Two ways to connect an ammeter, You can use a direct reading type, by connecting the ammeter in series with the load. You can use a current transformer type or CT. The current transformer looks like a wire wrapped donut with two terminals on its side with a hole through the middle. you pass the wire carrying the load through the center. Connect the direct reading meter to the two terminals. A CT type meter allows you to measure higher currents.
An ammeter is connected in series in a branch of the circuit carrying current, and measures the current in that branch. The resistance of the meter must be very low ... ideally zero ... in order to avoid influencing the circuit when it's installed. If you intentionally insert a resistance in series with the meter, then inserting the meter in a circuit changes the current in that branch. In general, it's not acceptable for the act of measuring to change the quantity being measured, unless you are closely related to Werner Heisenberg..
Just like voltmeters, ammeters tend to influence the amount of current in the circuits they're connected to. However, unlike the ideal voltmeter, the ideal ammeter has zero internal resistance, so as to drop as little voltage as possible as electrons flow through it. Note that this ideal resistance value is exactly opposite as that of a voltmeter. With voltmeters, we want as little current to be drawn as possible from the circuit under test. With ammeters, we want as little voltage to be dropped as possible while conducting current.