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I asked my husband who's an electrician and he say's a voltmeter does what it say's it measures "volts".
ANSWERVoltage is the potential difference between two points, thus a volt meter must be referenced somewhere (ie one probe connected to some location for comparison, often ground). You can think of voltage as the desire of electricity to flow. If you use a volt meter and measure an unused wall socket, you will read ~120 volts (AC, RMS), but there is no current (except the very small amount flowing through your meter), thus no energy (energy = power = voltage * current) is flowing from unused outlets.
A volt meter does not measure energy, it measures potential difference, or voltage.
ANSWER[it is a WikiAnswers violation to delete a technically accurate answer so that you can substitute your own]
OK, what we've got here is information being expressed at different levels of understanding and usage.
(1) An electrician only needs to know that his voltmeter measures something called "volts", without being concerned what "volts" means. If his voltmeter reads 117 volts here and 235 volts there, he knows whether or not the circuitry is working properly.
(2) A person reading a school textbook is going to be subjected to oversimplification, creative use of langauge and analogy rather than technically correct facts, easily misinterpreted partial truths, and the occasional totally incorrect information. When people start ascribing human characteristics like "desire" to electrical circuity, and use outdated or generic words like "electricity", you know they are operating at that middle school or high school level textbook level.
(3) A scientist or engineer needs to understand what is going on at a level of mathematical accuracy and within the accurately integrated framework of the International System of units and quantities. There is no le Systeme International quantity called "desire", and energy most certainly does not equal power. At this 3rd level of understanding, the language is constrained by information that conform to the internationally agreed-upon set of standards that we consider to be"scientific fact".
At this 3rd level of understanding, there are 2 competing but equally rigorous and correct systems for describing "electricity"; the 2 systems vary only by including or not including time as a factor. The system that does not include time is more fundamental, getting right down to the sub-atomic physics that drives electrical phenomena, so I prefer it. Let us call it FS for fundamental system. The popular le Systeme International includes time and is more likely to be encountered in textbooks of physics and engineering. It is almost always called SI.
So what does a voltmeter measure? FS explanation: As charge (measured in Coulombs) moves through a circuit, it must be driven by energy (measured in Joules). Voltage (or Potential Difference) is a measure of the amount of energy driving the charge at any point in the circuit. Voltage = energy/charge = Joules/ Coulombs=Volts.
The voltage always has to be measured between 2 different points in the circuit, so your voltmeter is telling you the difference between the energy levels at those 2 points. In order to read the energy levels, the voltmeter has to have a tiny amount of the charge move through the voltmeter; that's a critical understanding! The voltmeter can only read the energy difference by sampling some of the flow of charge. Having done that, your voltmeter can tell you in Volts the amount of energy driving the charge between the 2 points you selected.
So what does a voltmeter measure? SI explanation: As current (measured in Amperes) moves through a circuit, it must be driven by power(measured in Watts). Voltage (or Potential Difference) is a measure of the amount of power driving the current at any point in the circuit. Voltage = power/current= Watts/Amperes=Volts.
The voltage always has be measured between 2 different points in the circuit, so your voltmeter is telling you the difference between the power levels at those 2 points. In order to read the power levels, the voltmeter has to have a tiny amount of the current move through the voltmeter; that's a critical understanding! The voltmeter can only read the power difference by sampling some of the flow of current. Having done that, your voltmeter can tell you in Volts the amount of power driving the current between the 2 points you selected.
The only difference between the two explanations, as I said, is a time factor. Power is the energy delivered per second of time. Current is the charge flowing per second of time. So when you compare Power and Current, it is mathematically and physically identical to comparing Energy and Charge. The time factors cancel out and you're left with only a language difference.
If a circuit is energized or powered, as a convention we say that the operative voltages exist even though there is no charge or current flowing and the voltages are theoretically infinite. This is in recognition that the energy or power is instantly accessible whenever a load is introduced into the circuit.
What else can I help you with?
Would the reading be the same if the position f the voltmeter is changed?
No, changing the position of the voltmeter in a circuit can affect the reading due to the resistance and voltage drop across different components. It's essential to place the voltmeter in parallel with the component or points being measured to get an accurate reading.
How do you test a light bulb with a voltmeter?
To test a light bulb with a voltmeter, set the voltmeter to measure AC voltage. Then, place the voltmeter probes on the metal contacts at the base of the light bulb. If the light bulb is working properly, the voltmeter should display a voltage reading. If there is no reading, the light bulb may be defective and needs to be replaced.
What causes an error in reading a voltmeter?
Errors in reading a voltmeter can be caused by factors such as poor connection of the voltmeter probes to the circuit, incorrect range selection on the voltmeter, and external electromagnetic interference affecting the measurement. Additionally, using a voltmeter with low battery or a faulty internal circuit can also lead to erroneous readings.
Why a strip of mirror is mounted under the needle and near the scale of a voltmeter How this may help to rreduce errors while taking a reading?
The strip of mirror is mounted to help eliminate parallax errors when reading the value on the scale of the voltmeter. By aligning the needle's reflection with its actual position on the scale in the mirror, the observer can avoid viewing the needle from an angle, which could result in an inaccurate reading due to parallax. This setup ensures a more precise and accurate reading of the voltmeter.
Describe the proper placement of a voltmeter in a circuit?
To measure voltage in a circuit, the voltmeter should be connected in parallel across the component or portion of the circuit where the voltage is to be measured. Ensure the voltmeter is set to the appropriate voltage range before making the connection. It is important to place the voltmeter correctly to obtain an accurate voltage reading without affecting the circuit's operation.
What is the voltmeter reading this time?
positive terminal
Which type digital voltmeter is the of fatest all digital voltmeter?
You mean fastest? Digital voltmeter gives reading in seconds.
Would the reading be the same if the position f the voltmeter is changed?
No, changing the position of the voltmeter in a circuit can affect the reading due to the resistance and voltage drop across different components. It's essential to place the voltmeter in parallel with the component or points being measured to get an accurate reading.
What to do when voltmeter gives negative reading?
Cross the beams.
How do you test a light bulb with a voltmeter?
To test a light bulb with a voltmeter, set the voltmeter to measure AC voltage. Then, place the voltmeter probes on the metal contacts at the base of the light bulb. If the light bulb is working properly, the voltmeter should display a voltage reading. If there is no reading, the light bulb may be defective and needs to be replaced.
Will the rusting of nails in a sodium chloride - water solution effect the reading off a voltmeter or ammeter?
An ammeter or a voltmeter gives the reading of the flow of current, which is due to the movements of ions. When a rusted nail is immersed in the solution it will add the no of ions into the solution. This will increase the ion concentration and therefore will change the reading of a voltmeter and ammeter.
A multirange voltmeter which scale is numbered from 0 through to 250 the pointer falls mid range on the scale interpret the reading on the meter?
With the pointer mid range on the scale, the reading of the multi-range voltmeter would be 125 volts.With the pointer mid range on the scale, the reading of the multi-range voltmeter is 125 volts.
What causes an error in reading a voltmeter?
Errors in reading a voltmeter can be caused by factors such as poor connection of the voltmeter probes to the circuit, incorrect range selection on the voltmeter, and external electromagnetic interference affecting the measurement. Additionally, using a voltmeter with low battery or a faulty internal circuit can also lead to erroneous readings.
A 100 V voltmeter has full scale accuracy of 5 percent At its reading of 50 V it will give an error of?
A 100 V voltmeter has full-scale accuracy of 5%. At its reading of 50 V it will give an error of
Why a strip of mirror is mounted under the needle and near the scale of a voltmeter How this may help to rreduce errors while taking a reading?
The strip of mirror is mounted to help eliminate parallax errors when reading the value on the scale of the voltmeter. By aligning the needle's reflection with its actual position on the scale in the mirror, the observer can avoid viewing the needle from an angle, which could result in an inaccurate reading due to parallax. This setup ensures a more precise and accurate reading of the voltmeter.
Describe the proper placement of a voltmeter in a circuit?
To measure voltage in a circuit, the voltmeter should be connected in parallel across the component or portion of the circuit where the voltage is to be measured. Ensure the voltmeter is set to the appropriate voltage range before making the connection. It is important to place the voltmeter correctly to obtain an accurate voltage reading without affecting the circuit's operation.
Why does the total emf of dry cell in series not equal in the reading of voltmeter?
because in ckt connection there r done some ohmic loss due to the connecting wires and other factor , so voltmeter reading is not equal to its rated reading. and this also done due to different error like instrument error , measurement error etc...
