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Why does the current in a transformer fall when voltage increases?
Wiki User
∙ 9y ago
What happens to the voltage as the load is increased is determined by the characteristics (e.g. impedance) of the source. Let's look at Ohm's Law: E=IR Increasing load means lowering the resistance. Imagine putting a second R load in parallel with the first. The current will double. But it is not necessarily true that the source is capable of providing the increased current while maintaining its output voltage. Generally this information is provided by the Power rating of the supply. A supply where E=12 volts and the power rating is 120 watts, will deliver 10A continuously 12V X 10A = 120W. Beyond 10A the voltage cannot be maintained. Hope this helps!
Wiki User
∙ 16y ago
Wiki User
∙ 12y agoVoltage is lost along the wire conductor of the circuit - when in use - because even though the wire is a "good" conductor of electricity, there is some resistance, and that resistance uses energy and voltage drops across it.
This phenomemom is called VOLTAGE DROP
As the load is increased, more voltage is dropped across the circuit conductors.
AnswerThe behaviour you are describing is, in fact, due to the internal resistance of the voltage source -as well as for the reason described above.
When a voltage source, such as a battery or generator, is not connected to a load, its potential difference is simply the electromotive force (or 'no-load voltage') of that source. When a load is connected, a load current flows not only through the load itself, but also through the internal resistance of the source. This causes an internal voltage drop across the internal resistance, which acts in the opposite sense, or direction, to the electromotive force, thus reducing the voltage available at the terminals. The greater the load (i.e. the lower the load resistance), the greater the resulting load current, and the greater the internal voltage drop -and the lower the terminal voltage.
Wiki User
∙ 13y agoThey are inversely related to each other. Watts is the measure of power and will remain the same in your electrical system. The equation is
W=V x A where W is watts, V is voltage and A is amperes
so you can see that
W/V= A and W/A = V
Wiki User
∙ 9y agoIn common with most electrical circuits, when the voltage supply to a transformer is increased, the current through the windings also increases.
However, when the current drawn from the transformer increases (with the supply voltage unchanged), the voltage output from the transformer will be reduced.
Wiki User
∙ 11y agobecause of drop across internal resistance of transformer.
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Relationship between current and brightness of a light bulb?
the current is a factor that affects the brightness of the bulb but there are other factors such as if the circuit is in series or parallel. Overall though the current does affect the brightness of the bulbAnswerFor a lamp to operate at its rated power, it must be subject to its rated voltage. It's as simple as that! This is why a lamp's rated power is listed together with its rated voltage on the glass envelope of any lamp. If the voltage is allowed to fall below its rated voltage, then its power output will fall; in fact, a small fall in voltage will result in a proportionally-larger fall in power.
Does water particles fall to the earths surface after their temperature increases?
No when there density increases
How do you go from 480 volts to 240 volts?
I would like to know more about the application, but here goes. You can use a standard boost/buck transformer of 16/32 volts wired for buck of 16 volts and bring it to 239 vac. However depending on the application you may not have a problem with the voltage of 255 vac. You may attache a load to the system and see the voltage fall into the area of 240 vac once you are running. Saw it happen many times in practice.
What is the current sinking?
when you are floating and then you start moving and then you fall beneth water when you are floating and then you start moving and then you fall beneth water
How many amps in a circuit with 2 D cells and a resistance of 4 ohms?
A perfect typical D cell is 1.5V (alkaline slightly less) so two cells are 3.0V. The current flow would follow Ohm's law E=I*R or in this case I (current) = E (voltage) / R (resistance) or 3/4 = 0.75 Amps. Note that D-cells cannot for long supply this much current and the voltage from the cells will be less than 1.5V (due to the cell's internal resistance) and will fall off rapidly as they simply do not have the capacity to deliver this much current for very long.
What is current voltage transformer?
A transformer is a device that steps up, or steps down voltage. During this process current is also stepped up or down:however, voltage and current are inversely proportional ( meaning an increase in voltage results in a decrease in current and vice versa ) As an example: A step up transformer of 10:1 ratio with 12 volts and 10 amper of current applied to the primary will have ten times the voltage ( 120 volts ) and ten times less current ( 1 amrere ) at the secondary...and a step down transformer with the same turns ratio with 120 volts and 1 ampere applied to the primary will have 12 volts and ten ampere available at the secondary. The electricity supplied into homes and business uses wires carrying very high voltage and low current over long distances, then uses step down transformers to step down the voltage and step up the current. However, in power engineering and protective relaying applications, there are what are called "instrument transformers" which have the specific purpose of providing information to devices (such as relays or meters) about the voltages or currents in the power system. Therefore, there are some differences in construction and connectivity between a Current Transformer (CT) and a Voltage (or Potential) Transformer (PT). A CT will typically have a toroidal core and evenly distributed secondary windings so as to minimize leakage reactance. The primary is typically the main power line conductor, which passes directly through the toroidal core. This type of transformer is specifically for the purpose of measuring current values, and the secondary windings cannot be left open-circuited, or a large voltage will be produce, resulting in dielectric failure (and often an explosion). If a device is not connected to the CT, its secondary must be short-circuited. A PT is connected between the main conductor and ground and can be either wound in the normal way, or the voltage can be taken from a subsection of a string of capacitors (this is called a Capacitive Voltage Tansformer or CVT, and is usually cheaper than the wound type, but is typically not as accurate). This type of transformer measures voltage values, and the secondary winding cannot be short-circuited, as this will produce excessively high currents, resulting in the failure of the PT or the wires it is connected to. A PT can be left open-circuited.
What are the advantages of instrument transformer?
'Instrument transformer' is the collective name for current transformers (CTs) and voltage (or 'potential') transformers (VTs/PTs). These transformers have two functions:to reduce the current or voltage in a high-voltage primary circuit to values that may be measured using regular ammeters or voltmeters ('burdens'), or to provide the current or voltage inputs to protection relays.to electrically-isolate their secondary burdens from the high-voltage primary circuit for the purpose of safety.
Why are tap changing transformer are reguired?
When a transformer's load increases, the terminal voltage tends to fall. As there is a legal requirement for electricity supplies to remain within a certain tolerance of the rated nominal voltage (e.g. in UK residential voltages must remain within -6% and +10% of 230 V), it's necessary to slightly alter the turns ratio of the transformer when it's operating under load in order to maintain the required terminal voltage. This is the function of the tap-changer.
What will happen if the resistance of the conductor increased?
According to ohms law, V = IR, where V=voltage I= current R = resistance the above formula can also be written as I = V/R, here, resistance is inversely proportional to current. In other words, as resistance increases, current decreases.
What happen when voltage decreases and current increases?
Yes. As long as the load stays the same. Voltage equals the resistance of the load times the current or amperage. Or , in this case, as an example, if the load is the same, the voltage is 240 and current is 10 amps. At 120 volts, the current is 20 amps. Current x resistance(or the load)=voltage. With simple math, the equation can be moved around.
Why the output voltage drop when the load current is increase?
As the load current increases the losses in the circuit increases (I2R loss) and speed of the generator decreases so the voltage falls a little. and this voltage fall can be adjusted by increasing the speed of the generator and Iron losses are taken as constant losses.
Does the resistors current changes if the voltage across a fixed resistors is cut in half?
If the voltage across a resistor or resistors is halved, then the resulting current will also fall by half.
How does a voltage regulator regulate the voltage output of an ac generator?
Generator output is controlled by voltage feedback to the voltage regulator which senses voltage drop or rise and regulates the current being sent to the armature. This rise and fall of the armature current governs the generators output voltage.
Why should a transformer not be used on direct current?
Think of a transformer as a foot pump. Putting pressure on it will cause it to pump air but you need to release the pressure to do it again. The transformer does the same for electricity, if DC is applied to it it will create one pulse of current from the output but that is all. You need the continues rise and fall of AC to work the pump.
Why does a transformer need continuous rise and fall of current to induce a current into the secondary windings?
That is how inductance works. The rise is needed to charge the primary. When the field collapses, that is when the current is induced in the secondary winding(s).
Relationship between current and brightness of a light bulb?
the current is a factor that affects the brightness of the bulb but there are other factors such as if the circuit is in series or parallel. Overall though the current does affect the brightness of the bulbAnswerFor a lamp to operate at its rated power, it must be subject to its rated voltage. It's as simple as that! This is why a lamp's rated power is listed together with its rated voltage on the glass envelope of any lamp. If the voltage is allowed to fall below its rated voltage, then its power output will fall; in fact, a small fall in voltage will result in a proportionally-larger fall in power.
Can a transformer be used to transform direct voltage and direct current?
For all intents and purposes, none. Transformers pass alternating current. Now, if you want to split hairs, when a direct current is initially connected to a transformer, magnetic field starts to build in the primary windings, and as this field builds, the lines of force cut through the secondary windings, MOMENTARILY producing an output voltage in the secondary windings. However, once the magnetic field is stable (within a millisecond or so) the output of the secondary windings fall back to zero. When you remove the direct current from the primary winding, the same thing happens again. As the magnetic field collapses, the magnetic lines of flux cut through the secondary, momentarily producing an output voltage. After the magnetic field collapes completely, the secondary output is zero. That is basically what you are doing with alternating current...inputting a positive voltage, then going to zero, then negative, then back to zero, building and collapsing magnetic fields so that it induces current to flow in the secondary windings.
