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So it doesn't effect the circuit being tested. If a low impediance or resistance meter were inserted in the circuit, voltages may drop and effect the accuracy of the test. Any voltmeter will use some power from the circuit to make a reading. A "high impediance voltmeter" will use very little power from the circuit so the voltage reading will be as accurate as it can be.
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A DC voltmeter has a resistance of 20000 ohms per volt What is the resistance of the meter if the range selection switch is set on the 250 volt range?
5 megohms
Why are there more than two terminals on some ammeters and voltmeters?
A volt meter needs a high internal resistance not to influence the measurement, an ammeter needs a low internal resistance. Sometimes the easiest way to make that happen is to have different connectors.
What resistance value is add to convert a galvanometer into a voltmeter?
It depends on the resistance of the galvanometer and the current required to reach full scale. A 100 ohm meter requiring 1 milliampere would require 99.9 KOhms in series to become a 100 volt voltmeter.
How do you read 208 volts single phace circuit?
All voltage reading are usually read with a volt meter. This volt meter can be a hand held unit like electricians use.
How many millivolts in a volt?
that would be 1000. milli means one thousandth of the base unit (volt) millimeter is one thousandth of a meter. milliliter is one thousandth of a liter. milligram is one thousandth of a gram
Placing a voltmeter into a circuit will raise the circuit resistance?
Usually a volt meter is placed across a component to measure the voltage drop across that component. Doing this places the volt meter resistance in parallel with that component's resistance, which will always lower the total resistance. Since the volt meter resistance is usually very large relative to the resistance of the element being measured, the total resistance does not change significantly. The formula for total resistance of two parallel elements is: Rtot = (R1*R2)/(R1+R2), as R1 (the volt meter) >> R2, Rtot ~= (R1*R2) / (R1) = R2 If a volt meter is placed into a circuit instead of around an element of that circuit, it will raise the resistance of the circuit, load the circuit with, and interrupt "normal" operation of the circuit (normal operation = how things would be without the meter in place). More importantly, the volt meter would then be measuring the voltage developped across itself (instead of an element of the circuit), which is not the point of this tool / this would be a misapplication of a volt meter.
What is instrument potential transformer?
it is used to measure very high voltages which can not be measured with volt meter.
A DC voltmeter has a resistance of 20000 ohms per volt What is the resistance of the meter if the range selection switch is set on the 250 volt range?
5 megohms
Why don't we use an ammeter in series?
You do use an ammeter in series. It has a very low resistance, which according to ohms law, makes it ideal for measuring current. You do not use a volt meter in series, as it has a very HIGH resistance and would not allow current to flow. You measure the voltage across a component (or components), and current through a circuit.
Can insulation resistance of cable be checked with a volt meter?
No. A volt-ohmmeter will not check insulation. To check cable insulation you need a special device (called a megger) made for the purpose that imposes a high voltage and measures current leaks.
What is the most common brand of volt meter?
Fluke is a very good and very popular test meter.
Why are there more than two terminals on some ammeters and voltmeters?
A volt meter needs a high internal resistance not to influence the measurement, an ammeter needs a low internal resistance. Sometimes the easiest way to make that happen is to have different connectors.
What will happen if the voltmeter was inserted in place of an ammeter?
You would load the circuit, and it is likely it would not operate correctly. A volt meter is designed to have a very high resistance between the two probes; an ammeter is designed to have a very low resistance. For instance, say you have a 120 watt light bulb that runs on 120 volts (you would then draw ~1 amp of current). If you tried to measure this with a meter that has .1 ohm resistance on ammeter setting, and 1,000,000 ohms on volt meter: Error due to loading: ammeter: .1 / (120 + .1) = .08%; Current will be .999Amps, power to the light bulb will be 119.9 watts Volt meter: 1,000,000/ (120 + 1,000,000) = 99.9%; current will be 120micro Amps, power to the light bulb will be 14.4 milliwatts (the light bulb will not appear to be on).
An analog multi meter is quoted as having an accuracy of 1 k ohms and volt if it is set for FSD of 100v what is its loading resistance?
I think you mean the meter is rated at 1K ohms per volt. It means that with a series resistance designed to give FSD at any required voltage, the total series resistance must be 1000 ohms per volt (100K ohms for 100volts) . This is because 1K ohms per volt is just another way of saying that the full scale reading occurs at 1mA current. In that case a full scale deflection for 100 volts applied, 1mA is obtained with a total resistance (meter + added resistance) of 100 kOhms which is your loading resistance.
How do you check for amperage draw in a 12 volt car electrical system?
Place a current meter (rated for several hundred amps) in series with the battery. Or Place a large gauge wire of known resistance in series with your battery, use a high precision volt meter to measure the voltage drop across this piece of wire, then divide the measured voltage drop by the resistance of the wire. This will give you the current traveling through it.
What is the difference of volmeter and multimeter?
A volt meter can only measure voltage. A multimeter can measure other items such as resistance and continuity.
How does a volt meter work?
Electric field strength is a quantitative expression of the intensity of an electric field at a particular location. The standard unit is the volt per meter (v/m or v · m -1 ). A field strength of 1 v/m represents a potential difference of one volt between points separated by one meter. From: whatis.techtarget.com
