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By saying 'positive', you appear to be describing a d.c. system. In which case it depends entirely on the potential difference of the source and how it is earthed. If you are describing an a.c. system, then you presumably mean 'line', rather than 'positive', then -again- it depends on the potential difference of the source and how it is earthed -e.g. in the UK, the potential of the line, measured with respect to earth, should be close to the nominal value of 230 V.
Incidentally, there is no such thing as 'voltage potential'. 'Voltage' is synonymous with 'potential difference', not'potential'. So, when you say 'voltage potential', it's the same as saying 'potential difference potential' which, I think you will agree, doesn't make any sense!
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∙ 12y ago
Wiki User
∙ 14y agoThe electric potential of the earth is zero (0) because earth is neutral.
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Voltage across Neutral and earth for a 3 phase auto transformer?
A grounded neutral will be at earth potential. A floating neutral will be at a voltage dependent upon the voltage imbalance between phases, and the design of the transformer.
Is voltage the same as potential?
volt drop and potential difference are effectively the same thing, although the term volt drop is usually used in reference of what voltage has to occur for a diode to conduct, or what volt drop is expected across a long wire etc, potential difference is used to refer to the difference in voltage over a potential divider.
Why voltage are not produce in netural wire?
First of all, by definition, 'voltage' is another word for 'potential difference', and a potential differenceexists between two different points. So a single conductor cannot experience a 'voltage' or 'potential difference'. Your question, therefore, should ask why a neutral conductor has no 'potential'. By general agreement, potentials are measured with respect to earth (ground), which is arbitrarily assumed to be at 0 volts.The answer is that a neutral conductor is earthed, or grounded, so theoretically its potential must be the same as earth -i.e. 0 volts. But, in practise, due to the resistance of the conductor that connects the neutral conductor to earth, the neutral conductor can often have a potential of several volts with respect to earth.
What is the potential difference between earth wire and live wire?
In formal electrical jargon, "potential difference" describes voltage. So a 120 V live wire should have a 120 V potential to the earth wire.AnswerIt depends where you live. In Europe, the nominal potential difference between a line and earth conductor is approx 230 V (approximately, because earth potential might be a little lower than the neutral potential); for North America, the nominal potential difference is about 120 V.
How do you calculate 3 phase earth fault loop?
You can't have a three phase earth fault, you can have a phase to phase or a phase to earth fault. If you want the potential phase to earth fault current it will be your voltage times your impedance. If you want the phase to phase potential fault current then you should just double the above result.
How can you get negative voltage?
Your question should read "How do you get a negative potential?", for the reasons explained below.The term, 'voltage', is another word for 'potential difference'. The terms 'positive' and 'negative', when applied to a potential difference or voltage indicates the sense (or direction) in which the potential difference or voltage is acting. For example, if a second voltage is acting in the same direction as another voltage then it is acting in the positive sense; if it is acting in the opposite direction then in is acting in the negative sense'.It's very important to understand that you cannot apply 'positive' and 'negative' is the sense of charge or polarity to potential difference or voltage. You can, however, apply these terms to 'potential'. Potential is relative, and always measured with respect to a given point (often, the earth). So a point can be, for example, +5 V or -5 V with respect to another point (usually earth or ground, but not necessarily).Never confuse 'potential' with 'potential difference' and remember that 'voltage' means potential difference notpotential.So, to obtain a negative potential, earth (ground) the positive terminal of the battery or d.c. supply. All potentials measured relative to earth are now negative. To obtain a positive potential, earth the negative terminal of the battery or d.c. supply instead. All potentials measured relative to earth are now positive.If you want to get a negative potential,Earth the positive terminal of the DC power sourceConnect a resistor in series with the negative terminal of the sourceAt the other end of the resistor you get a negative potential (the value's less than the value of the power supply)
Why the dc average voltage is having negative value?
Voltage is synonymous with 'potential difference', and cannot have a positive or negative value (in the sense of charge). So what you are describing is 'potential', which can. So, for example, a battery whose positive terminal is earthed or grounded will indicate a negative potential if a voltmeter is connected between earth and its negative terminal.
The unit of electric potential difference between two points is?
You can compare 'potential' with height, and 'potential difference' with the difference in height.The height of an object depends upon from where you measure it. For example an object three-quarters of the way up a 1000 m mountain is +750 m from the base of the mountain, but -250 m from the top of the mountain. Note how we apply a positive or a negative sign to indicate whether we are measuring upwards or downwards.The same applies to potential. It's value depends upon from where it is measured. For example, two charged objects could have a potential of , say, +5 V with respect to earth (ground) and a potential of -15 V with respect to earth. But the potential difference between them will be +5 - (-15) = 20 V.Notice how, in the above example, we always show a positive or negative sign when we talk about potential, but we don't use these signs when we talk about a potential difference. Furthermore, it is important that we must ALWAYS specify the reference point when we describe potential -e.g. "What is the potential at point A, with respect to (say) earth?"Taking this further. It's important to know that the term 'voltage' means 'potential difference', and not'potential'! It would be quite wrong to say that the 'voltage of an object is (say) -200 V with respect to earth'. The correct expression would be the 'potential of an object is -200 V with respect to earth'.
Why neutral have zero voltage?
Your question should read, 'Why does a neutral have zero potential?' 'Voltage' means 'potential difference', and you cannot have a potential difference at a single point. A neutral doesn't necessarily have zero potential although it is connected to earth (ground). This is because the potential of earth isn't literally zero; it's just considered to be zero, in the same way that sea level is considered to be zero in terms of height. Furthermore, there is often a voltage drop between the neutral and earth -in which case, the potential of the neutral can be several volts higher than the potential of earth.
Voltage across Neutral and earth for a 3 phase auto transformer?
A grounded neutral will be at earth potential. A floating neutral will be at a voltage dependent upon the voltage imbalance between phases, and the design of the transformer.
Is voltage the same as potential?
volt drop and potential difference are effectively the same thing, although the term volt drop is usually used in reference of what voltage has to occur for a diode to conduct, or what volt drop is expected across a long wire etc, potential difference is used to refer to the difference in voltage over a potential divider.
Why voltage at neutral in ckt is zero?
You really should be asking why the potential of neutral is zero. 'Voltage' means 'potential difference' which, by definition, cannot exist at at point. The reason is that the neutral conductor is earthed (grounded), and earth is, by general consent, considered to have a potential of zero volts. In practise, however, there is usually a small voltage drop between the neutral and earth, so it would be more accurate to say that the neutral's potential is close to zero.
What is positive and negative dc voltage?
They are opposites of each other. This refers to the direction of the electrical current is flowing. A battery right side up has +4.6 volts across it. Current is flowing out of the top and I to the bottom. Flip it upside down, now measured the same way you'll see -4.6 volts, meaning current if flowing into the top and out of the bottom.Additional AnswerThere is no such thing as a 'positive' and 'negative' voltage if you are referring to 'positive' and 'negative' in the sense of polarity or charge. Voltage is simply another name for potential difference, and you cannot have a positively- or negatively-charged potential difference! Presumably, what your question should ask is "What is positive and negative potential?".The potential at any point in a circuit is measured with respect to another point in the same circuit -often, this is earth (or ground). For example, a car battery's negative terminal is usually earthed to the vehicle's metal chassis, so anything connected directly to its positive terminal has a potentialof +12 V.On the other hand, 'positive' and 'negative' can also refer to sense or direction, rather than polarity or charge. Used in this sense, you can apply these terms to potential difference or voltage. For example, if a second battery acts in the same direction as another battery, then its voltage is acting in the positive sense (or direction); if it is connected to oppose another battery, then its voltage is acting in the negative sense. Applying the terms 'positive' and 'negative', in this sense, to potential differences or voltages, is useful in various electrical theorems, such as Kirchhoff's.
Why voltage are not produce in netural wire?
First of all, by definition, 'voltage' is another word for 'potential difference', and a potential differenceexists between two different points. So a single conductor cannot experience a 'voltage' or 'potential difference'. Your question, therefore, should ask why a neutral conductor has no 'potential'. By general agreement, potentials are measured with respect to earth (ground), which is arbitrarily assumed to be at 0 volts.The answer is that a neutral conductor is earthed, or grounded, so theoretically its potential must be the same as earth -i.e. 0 volts. But, in practise, due to the resistance of the conductor that connects the neutral conductor to earth, the neutral conductor can often have a potential of several volts with respect to earth.
What is the difference between potential difference and voltage difference?
To specifically answer the question, there is no such thing as 'voltage difference' because, by definition, 'voltage' means 'potential difference' -not 'potential'!You can compare 'potential' with height, and 'potential difference' with the difference in height.The height of an object depends upon from where you measure it. For example an object three-quarters of the way up a 1000 m mountain is +750 m from the base of the mountain, but -250 m from the top of the mountain. Note how we apply a positive or a negative sign to indicate whether we are measuring upwards or downwards.The same applies to potential. It's value depends upon from where it is measured. For example, two charged objects could have a potential of , say, +5 V with respect to earth (ground) and a potential of -15 V with respect to earth. But the potential difference between them will be +5 - (-15) = 20 V.Notice how, in the above example, we always show a positive or negative sign when we talk about potential, but we don't use these signs when we talk about a potential difference. Furthermore, it is important that we must ALWAYS specify the reference point when we describe potential -e.g. "What is the potential at point A, with respect to (say) earth?"Taking this further. It's important to know that the term 'voltage' means 'potential difference', and not 'potential'! It would be quite wrong to say that the 'voltage of an object is (say) -200 V with respect to earth'. The correct expression would be the 'potentialof an object is -200 V with respect to earth'.
What is potential difference or voltage?
If you take two different nodes in a network and if you find the difference in voltage for those nodes then it is known as potential or voltage difference. Here the reference is not taken. But if you find potential difference between a node and its respective ground it is known as voltage at that node here reference is ground potential i.e zero.Answer'Voltage' is synonymous with 'potential difference'; they both mean the same thing. And it is important that these terms are not confused with 'potential'. So, it is incorrect to say 'voltage difference' (which would mean 'potential difference difference'!), or to describe a voltage as existing 'at' a particular point, or 'with reference to', for example, earth or ground.In very simple terms, if two points are at different potentials, then there is a potential difference (or 'voltage') between them. A potential exists when work is done moving a charge to a particular point; the greater the work, the higher the potential. 'Potential' is roughly equivalent to the potential energy gained by an object when it is lifted against the force of gravity.Think of it this way: 'potential' is equivalent to 'height', whereas 'potential difference' (voltage) is equivalent to the difference between points at different heights.
Explain how positive and negative voltages can exist at the same time in a circuit but with only one voltage source?
Voltages are relative. You could, for example, build a simple resistor voltage divider with two resistors and choose the middle point as ground. You would have minus and plus voltages relative to that point then.It is also possible to generate minus voltage (relative to voltage source) with more complex circuitry from a single source. The circuit is called a charge pump.AnswerPositive voltage exists between the power source, and the load (Load being whatever device is being powered). Negative voltage exists between the load and the ground, or negative terminal.AnswerYour question (and the two answers, above) confuses potential difference with potential. 'Voltage' is synonymous with 'potential difference', not 'potential'.The two answers, above, are each describing 'potential', not 'voltage'. There is no such thing as a 'positive' or 'negative' voltage in the 'charge' sense. Voltages are absolute, whereas potentials are relative. So, if one point has a potential of +10 V with respect to, say, earth, and a second point has a potential of -15 V, then the voltage (potential difference) between them is 25 V (no sign!).We can, on the other hand, apply signs to voltages if those signs are used to describe 'sense' or 'direction' in which a voltage is acting. For example, if two batteries are wired in opposition, we can say that the second voltage is acting a 'negative' sense to the first voltage.We do this when we apply Kirchhoff's Voltage Law to a series circuit, when we write an expression such as: V1 +V2 -V3 = 0In the above equation, we are saying that voltages V1 and V2 are acting in one direction, while voltage V3 is acting in the opposite direction.
