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well a voltmeter measures AC and DC voltage. resistance is a term used only for DC voltage, A voltmeter uses a term called Impedance for AC, without it, when you measure across two terminals it would create a short circuit and would blow up the meter. it is basically a safety feature to prevent people from creating short circuits when measuring.
Wiki User
∙ 16y ago
Wiki User
∙ 11y agoB/c a voltmeter is connected in parallel with what you want to measure the voltage over, and if it had a low resistance, the current would flow through the voltmeter instead, changing the circuit and givign you a measureing error.
Wiki User
∙ 14y agoThe voltmeter has high resistance so as to minimize the error introduced in the measurement caused by changing the resistance of the circuit when you connect the meter.
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What is the use of universal high resistance voltmeter?
A voltmeter must have a very high resistance to measure voltage. A voltmeter is placed in parallel with the element that you are measuring. If the voltmeter has a low internal resistance, then all of the current will flow through the voltmeter instead of the element. You want all of the current to flow through the element, to get an accurate reading of the voltage. Conversely, an ampmeter must have zero resistance, because it is placed in series with the element.
Why is the resistance of volt meter very high?
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.
What is loading affect of multimeter?
'Loading effect' applies to voltmeters, or to multimeters when set to measure voltage. It describes the change in a circuit's resistance when the resistance of the voltmeter is taken into account. It's effect is to cause the resulting measuredvoltage to be different from the actual voltage which would appear without the voltmeter connected. The loading effect is minimised by ensuring that the internal resistance of the voltmeter is significantly higher than the resistance of that part of the circuit to which it is connected. For general voltage measurement, this is usually the case anyway, but when measuring circuits which, themselves, have very high resistance care must be taken over the choice of voltmeter to be used.
Why must voltmeter be connected in parallel with the circuit component?
Because, by definition, a voltage is the difference in potential between two different points. So the voltmeter must be connected across those points in order to measure that voltage -i.e. in parallel with the points.B
What happens when a voltmeter is connected in series with load?
when we connected voltmeter in series it takes large current and voltage and the resistance is considerably decreases.this is why we had connected voltmeter in series combination.
Convortion of moving coil galvanometrr into voltmeter?
A galvanometer can be converted into a voltmeter by connecting it with very high resistance.
What is the use of universal high resistance voltmeter?
A voltmeter must have a very high resistance to measure voltage. A voltmeter is placed in parallel with the element that you are measuring. If the voltmeter has a low internal resistance, then all of the current will flow through the voltmeter instead of the element. You want all of the current to flow through the element, to get an accurate reading of the voltage. Conversely, an ampmeter must have zero resistance, because it is placed in series with the element.
Why do you get different results when calculating the voltage drop across a resistor and ignoring resistance of a voltmeter and when considering it?
Voltage drop is the product of current and resistance. When you connect a voltmeter across a resistor, you are connecting that voltmeter's internal resistance in parallel with that resistor. The resulting resistance of this parallel combination is lowerthan that of the resistor. As a result the voltage drop (current times this lower resistance) will be lower than it would be without the voltmeter connected. This is called the 'loading effect' of that voltmeter.The higher the internal resistance of the voltmeter, the less effect it will have on lowering the overall resistance when connected across a resistor. This is why the internal resistance of a voltmeter is made deliberately very high. Under most circumstances, therefore, a conventional voltmeter will have very little effect on the resistance of the circuit being tested and, so, it will have no significant effect on the voltage appearing across the resistor.However... for circuits that already have exceptionally-high resistance values, you must be careful when you select a voltmeter as you must take into account its internal resistance and ensure the voltmeter you use has the very highest internal resistance available. This is because the loading effect increases with circuits that have a high resistance. That might involve selecting a voltmeter that works on a completely-different principle , such as an electrostatic voltmeter or, perhaps, an oscilloscope
If a voltmeter is hooked up in series it will?
It will prevent almost all current from flowing the circuit, since a voltmeter has a very high electrical resistance. Only ammeters (or milliammeters) should be wired in series between a power source and its load.
Why does voltmeter have high internal resistance?
No, ammeters have a low internal resistance. This is so that when they are put in series with a circuit, they change the circuit's operating characteristics as little as possible.Contrast this with voltmeters, which do have a high internal resistance, and which are intended to be placed in parallel with the circuit they are measuring.Use the link below to the related question on why ammeters have a low internal resistance and read through that information to see why things are the way they are.
Why is the resistance of volt meter very high?
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.
High resistance in parallel connected with galvanometer to form voltmeter?
That won't work. To convert an ammeter (a galvanometer is a very sensitive type of ammeter) you connect a high value resistor in series with it.
What is loading affect of multimeter?
'Loading effect' applies to voltmeters, or to multimeters when set to measure voltage. It describes the change in a circuit's resistance when the resistance of the voltmeter is taken into account. It's effect is to cause the resulting measuredvoltage to be different from the actual voltage which would appear without the voltmeter connected. The loading effect is minimised by ensuring that the internal resistance of the voltmeter is significantly higher than the resistance of that part of the circuit to which it is connected. For general voltage measurement, this is usually the case anyway, but when measuring circuits which, themselves, have very high resistance care must be taken over the choice of voltmeter to be used.
Why the series resistor of the voltmeter is high?
Aim of any measuring instrument is to measure the object without affecting it. Voltmeter is used to measure voltage between two points and connected in parallel. Thus voltmeter should not change the voltage. If voltmeter resistance is very high, it will be as good as infinity compared to load. Thus connecting voltmeter will not change the voltage and measure it accurately.
Why must voltmeter be connected in parallel with the circuit component?
Because, by definition, a voltage is the difference in potential between two different points. So the voltmeter must be connected across those points in order to measure that voltage -i.e. in parallel with the points.B
An accurate voltmeter must have an internal impedence of?
very high value
What happens when a voltmeter is connected in series with load?
when we connected voltmeter in series it takes large current and voltage and the resistance is considerably decreases.this is why we had connected voltmeter in series combination.
