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Why less voltage drop with 240 wire vs 120 wire for the same length of run?
Wiki User
∙ 13y ago
Voltage drop in wire is determined by the "gauge" of the wire, which is the thickness of it. A 12 gauge wire is thicker than a 14 gauge wire. The 14 gauge wire will have more voltage drop caused by the current passing through it because it is smaller and has more resistance.
Voltage drop will also be affected by the amount of voltage on a wire. It would be incorrect to assume that voltage drop is a percentage based on the length of the wire. The wire gauge affects the resistance of the wire, but assuming the same size (gauge) of wire, a higher voltage will have a greater force behind it than a lower voltage so essentially the resistance of the wire doesn't affect higher voltage as much as it does lower voltages.
If you were to compare electrical wiring with Plumbing, voltage would be equivalent to water pressure, and amps would be equivalent to flow, or gallons per hour.
Additional Comments and Answer for European Electrical Installations
The questioner probably really means "Why is there less voltage drop for a cable operating at 240 V, compared to the same cable operating at 120 V".
If this is the case, then the answer is simple. For a load of any given power, the higher the voltage, the lower the resulting current. For example, let's suppose we have a 1000-W load operating at 230 V -this load will draw a current of 4.35 A. The same load operating a 120 V will draw a current of 8.33 A. So, for any given conductor size, the voltage drop (Iload x Rconductor) will clearly be greater.
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Before you do any work yourself,
on electrical circuits, equipment or appliances,
always use a test meter to ensure the circuit is, in fact, de-energized.
IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
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∙ 13y ago
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How can we check the starter's external wiring circuit for volt drop?
For voltage drop checking on the wire from the battery positive post to the starter main terminal, you place the voltmeter reading on the 1 to 3 volt range, (or what lower range you have). You then place one voltmeter lead on the positive battery post, the other lead you place on the starter positive terminal and have someone crank the engine. While the engine is cranking, you observe the voltage drop. It should be less than a volt. This seems strange because you would think the cable would not drop voltage but it sure can. If the battery post is dirty or bad connection, you could see a voltage drop all the way to the maximum 12 volts battery voltage depending upon the connection. Also you can check the return path the same way--- Negative case of the starter to the negative post on the battery for voltage drop. If it is more than a volt or two, you have a bad ground return circuit.
If the resistance in the circuit is increased what will happen to the current and voltage?
* resistance increases voltage. Adding more resistance to a circuit will alter the circuit pathway(s) and that change will force a change in voltage, current or both. Adding resistance will affect circuit voltage and current differently depending on whether that resistance is added in series or parallel. (In the question asked, it was not specified.) For a series circuit with one or more resistors, adding resistance in series will reduce total current and will reduce the voltage drop across each existing resistor. (Less current through a resistor means less voltage drop across it.) Total voltage in the circuit will remain the same. (The rule being that the total applied voltage is said to be dropped or felt across the circuit as a whole.) And the sum of the voltage drops in a series circuit is equal to the applied voltage, of course. If resistance is added in parallel to a circuit with one existing circuit resistor, total current in the circuit will increase, and the voltage across the added resistor will be the same as it for the one existing resistor and will be equal to the applied voltage. (The rule being that if only one resistor is in a circuit, hooking another resistor in parallel will have no effect on the voltage drop across or current flow through that single original resistor.) Hooking another resistor across one resistor in a series circuit that has two or more existing resistors will result in an increase in total current in the circuit, an increase in the voltage drop across the other resistors in the circuit, and a decrease in the voltage drop across the resistor across which the newly added resistor has been connected. The newly added resistor will, of course, have the same voltage drop as the resistor across which it is connected.
What is the meaning of IR of voltage?
In Ohm's Law, E stands for voltage, I stands for current (amps), and R stands for resistance. Ohm's Law states: E = IR or voltage equals current times resistance. This means that current flowing through a wire (that has resistance) produces a voltage drop in the wire. Since the voltage drop is the result of current flowing through a resistance, old-school engineers will sometimes refer to it as "IR drop". So, since E = IR, saying "IR" is the same as saying "voltage".
Why does the voltage drop as electricity flows through a light bulb?
Do you mean why is the voltage in a circuit lower after the light bulb than before it? If so, it's because the light bulb filament has electrical resistance. When an electrical current flows through a resistance, there is a voltage drop across the resistance (Ohm's law).More fundamentally, the light bulb is producing light, which is a form of energy. The voltage drop across the light bulb comes from the fact that electrical energy is being turned into light. If voltage didn't drop, you would be producing energy from nothing. Furthermore, if there were no voltage drop, your circuit would behave the same whether you had no light bulbs, one light bulb, or eighteen million light bulbs - something that clearly can't be the case.
Why does voltage change across components but not current?
we know,v=IRresistor, capacitor, inductor and other electrical components have their own specific characteristics to drop voltage or to consume voltage at a fixed amount.the supplied voltage produces a current that changes with the change of the voltage. It doesn't changes simultaneously. so the voltage change across the components. but the current doesn't changes across component...AnswerThink of a circuit with several loads as being rather like a number of central heating radiators connected in the same way. The same water (current) flows through each radiator. In order for that water to flow, we need a pump to supply pressure (supply voltage) across all the radiators. At the same time, there must also be a pressure difference (voltage drop) across each individual radiator or the water wouldn't flow through it. The sum of these individual pressures must add up to equal the pressure supplied by the pump.So the same current flows through individual loads, driven by the supply voltage applied across the entire circuit. At the same time, there must also be voltages across individual loads (called 'voltage drops'), or current wouldn't be flowing through them. The sum of the individual voltage drops will equal the supply voltage.
What is the voltage drop running through the parallel?
The voltage drop is the same through each of the parallel branches.
What is the voltage drop running through the parallel potion of the circuit?
A: There is no voltage drop running through in a parallel circuit but rather the voltage drop across each branch of a parallel circuit is the same
What is the voltage drop in diode IN4007?
forward drop is the same as any other silicon diode, about 0.7V
How does voltage drop effect the amps?
Yes. When the voltage drops and the power requirement (watts) stays the same, the amperage goes up.
Can I use a laptop ac adapter with the same volts but higher amps?
Yes. The current rating listed is the _maximum_ current that the power supply can provide without a drop in voltage.
Is it true that Less watts will be spend when low voltage?
Yes. If you reduce the voltage to the same device, then it uses less power.
What is voltage drop per foot?
Voltage drop is caused by resistance. From the equation V=IR the voltage across that resistance can be calculated. For a uniform conductor the resistance is linear with the length R=kx where k is in ohms per foot. For a given current, the voltage drop V=Ikx so the voltage drop per foot is Ik. Voltage drop per foot can be measured, allowing a calculation of voltage drop for very long lengths of conductor such as power transmission lines. This is a reasonable approximation as long as the total voltage drop in transmission is small relative to the supply voltage. If the voltage drop is large, the current will be limited by the total resistance. This implies that long distance transmission lines should be high voltage, because 1 megawatt at 10,000 volts requires 100 amps, while at 100,000 volts it only requires 10 amps. The voltage drop per foot for the same conductor would be 10 times as large at 10 times the current, and the power loss (I*IR) would be 100 times as large. For alternating current, inductance can be a factor; this implies that relatively low frequency would be preferred.
How is voltage reduced when using power tools on site?
If you are working from a generator and many tools are used at the same time, voltage will drop.
If two resistors have same voltage drop in a series circuit it means?
It means the two resistors have same resistance
Is voltage drop across each device the same in household circuits?
No, even though these are parallel circuits, the voltage drop across each device is not the same in house hold circuits, or anywhere, for that matter. Different devices pull different currents. A toaster, for instance, pulls many times what a light bulb pulls. Since wires do not have truly zero resistance, those differing currents result in different voltage drops across the wires that lead to the devices. That small voltage drop in the wires results in a different voltage drop across each device, even though the device/wire is connected to the same voltage source.
Will 3 60W globes glow more brightly when they are connected in series or parallel?
In parallel they will be brighter because there will be the same voltage drop and the same current through each. In series they will each have 1/3 the voltage and current. Since the current heats up the filament lesser current is less light.
Why do you always speak about voltage drop and not current?
Voltage is like the pressure in your hose pipe. Current is the flow of charge and equivalent to the rate of flow of the water. Due to resistance to the water in the pipe,the pressure of the water will reduce along the length of the pipe but the quantity of litres flowing in the pipe will not change. So voltage will be maximum at the source of the voltage but as you move along the conductor there is voltage drop due to the resistance of the conductor.However, the current is same at all points along the conductor (the flow of charge is uniform at all points)
