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Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
Is hysteresis loss considered heat loss?
In general even though energy is lost during hysteresis it is not called as heat losses . Generally I2R losses are called as heat losses because in these tye of only in these energy is lost in the form of real heat
Why transmitting of power at high voltage is economical?
For a given load, the higher the supply voltage, the lower the resulting load current. So, using high-voltages in transmission systems (1) avoid enormous voltage drops along the line, (2) enable cables of realistic cross-sectional area and weight to be used, and (3) minimise line losses. So, high-voltage transmission requires less copper and avoid line losses -resulting in lower costs.
Will changing an electric motors input from 115 volt to 230 volt cause motor to run at 3450?
Yes, IF the motor is a dual-voltage motor to begin with. There should be re-connection instructions on the motor nameplate, or available from the manufacturer. The motor will list both voltages on the nameplate. If it only lists one, then the motor cannot be re-wired to a different voltage.
Where Subsynchronous resonance use?
It's use while making love with your partner. During the pumping process a proper synchronisation has to maintained by both the bodies. Any imperfection can lead to the development of torrisioal stress on the shaft which can thereby result in premature ejaculation or even permanent damage/failure of shaft.
Remedy: DO ORAL
What is the principle of Electric Chimney?
Electric chimneys are designed for use in the kitchen. They fit over a stove and filter out smoke and oil from cooking. The air that is sucked into the chimney is then released outside the house or business through a duct in the roof.
AC stands Alternating Current, a type of electricity that changes constantly from one polarity to another(like what you get from the wall outlets). DC stands for Direct Current, a type of electricity that maintains its polarity all the time(like what you get from a battery). AN AC/DC converter is something that turns outlet-type electricity into battery type electricity.
RECTIFIER s can convert ac to dc.the different types of rectifiers are halfwave,full wave,bridge rectifier.by connecting capactor to all of the above mentioned ckts efficiency can be enhanced.
What is the function of a summation current transformer?
Current transformers are used to measure electric currents. When current in a circuit is too high to directly apply to measuring instruments, a current transformer produces a reduced current accurately proportional to the current in the circuit, which can be conveniently connected to measuring and recording instruments.
What device employs mutual induction?
Mutual inductance OR induction refers to two independent coils which are electrically isolated but magnetically coupled through a path of low reluctance .This will cause most of the energy produced in the primary side to transfer to the secondary with minimal losses.That is why transformers which functioning on the principle of mutual induction has efficiency nearly 99%.
One of the lights in the string that isn't working is faulty. Try replacing them one by one. Turn the power off each time you change a light.
Where is Champion generator made?
Champion generators are manufactured in various locations, primarily in China. The company, Champion Power Equipment, is based in the United States, but the production of their generators takes place overseas to manage costs and meet demand.
I guess it depends on the design of the generator. In the plants I know in th UK it is usually 11 KV
What are the applications of losses in transmission line?
There are no applications for losses, that's why they are called 'losses'!
Can you use a 240 volt 3 phase disconnect with 460 volt?
It's possible, but not at all economic. Usually the 240V (sure it's not 277?) has been stepped down from 480V service already. Sounds like this is a commercial application. 480 is rare in residential, but quite common in commercial. If you need 480, you'll need to get ahead of the step down transformer.
AnswerYou cannot obtain a three-phase supply from a single-phase supply.
Can you get a 3 phase supply by using three single phase supply?
Not that easily. A three-phase system can be broken out into three separate single-phase supplies, but in the three phase system the three supplies must have the right phase relationship, spaced apart in time by one third of a cycle always.
The reason for that is that we can consider each separate supply as having a live wire and a neutral wire. With a 3-phase system if the three neutral wires are comined into one neutral wire, the current in that single neutral wire is zero - provided all three live wires supply equal currents and the right phase relationship is maintained.
What paths can electricity take through a series circuit or a parallel circuit?
electricity take every possible path which follow closed path across its source.
In a series circuit, there is only one path for current to flow; the same current passes through each component.
In a parallel circuit, there are multiple paths called 'branches', and the sum of the individual branch currents is equal to the current drawn from the supply.
Where is the amplifier for the 1991 Lexus LS400 located?
Doyou mean LS400 lexus? The amplifier is integrated with the radio that power the speakers. Be aware that removing the radio on a LEXUS it may not work afterward because of a memory code installed into the radio to make inpossible to steal it.
Capacitor used in motor for starting torque?
A capacitor builds and holds a charge until required. Larger motors require a temporary boost in electrical power in the start-up phase in order to overcome the inertia of a motionless stator. Once the stator begins to spin, the capacitor disengages from the starting circuit.
AnswerCapacitors are used to provide the starting torque for single-phase induction motors. They do this by causing the current through the starting winding to be out of phase with the current through the main winding, causing the resulting magnetic fields to naturally rotate, cutting the bars of the rotor, and inducing voltages into them. The resulting combination of fields provides the starting torque on the rotor. Once the machine is running, this amount of torque is no longer necessary and the capacitor is disengaged. Further to the original answer, the charge on a capacitor cannot 'build up and hold' when subjected to a.c., and most certainly cannot provide a 'boost' -temporary or otherwise!
In physics, a dielectric is an insulating (or very poorly conducting) material. The material can be solid, liquid or gaseous. When a voltage difference is applied to top and bottom of a cylinder filled with a dielectric, no current will flow inside the cylinder because, unlike metals, a dielectric has no free-or loosely bound-electrons that can drift through the material. Instead, electric polarization occurs. The positive charges within the dielectric are displaced minutely in the direction of lower voltage, and the negative charges are displaced minutely in the opposite direction. When the molecules constituting the dielectric are polar (like water molecules), the molecules will align in the field, thus contributing to the electric polarization. Inside the cylinder no net charge density will arise because the charges in adjacent volume elements cancel. However, at the top and bottom of the cylinder an uncanceled surface charge will appear, and this surface charge (positive at the low voltage side and negative at the high voltage side) will oppose the electric field associated with the voltage difference. Thus, the polarization of the dielectric reduces the electric field inside the dielectric. Dielectric material is characterized by an intrinsic property called relative permittivity, usually denoted by εr (formerly this was known as the dielectric constant). The relative permittivity describes the ease of the polarization of the material and determines the size of the surface charge densities at the top and bottom of the cylinder. The Coulomb force between two permanent electric point charges placed inside a dielectric medium is 1/εr smaller than it would be in a vacuum due to the polarization of the dielectric medium by the point charges. The quantity of electric energy stored per unit volume of a dielectric medium is proportional to εr. The capacitance of a capacitor filled with a dielectric is a factor εr greater than it would be in vacuum. Reference: http://en.citizendium.org/wiki/Dielectric
Dielectric is a substance that can transport electricity without conducting it.
What is the degree to which a substance resists flow known as?
For resistance to electrical flow, the term is specific resistance of a substance.
The resistance of a fluid (gas, liquid) to flowing is called its viscosity, referred to colloquially as its thickness.
Do all electrical and electronic circuits obeys ohms law?
Ohm's law is always true. That's what makes it a law. What trips people up is that resistance is not constant. The law states that voltage is current times resistance. That is true, no matter what. The calculations can become complex, because resistance is not constant.
Another AnswerProbably not. But it really depends on the shape of the characteristic curve for its application (e.g. diode).Despite being fundamental, Ohm's Law is one of the least understood so-called 'laws' in electrical engineering. It applies in so few cases, in fact, that many engineers and physicists argue that it should not be called a 'law' at all!
Ohm's Law is not a universal law, and onlyapplies when the ratio of voltage to current is constant for variations in voltage. This only applies to linear or 'ohmic' devices. Most electronic devices are non-linear or 'non-ohmic' and these include vacuum tubes and solid-state devices, etc. Even some pure metals, such as tungsten, are non-linear -so incandescent lamps, for example, do not obey Ohm's Law.
Ohm's Law only applies to conductors and circuit devices that produce a straight-line graph when current is plotted against variations in voltage. If the resulting graph is curved, then Ohm's Law doesn't apply. Period!
Think about it: if you, say, double the voltage for a curved graph line, the resulting current doesn't double in value -so it can't be obeying Ohm's Law (which states that 'current is proportional to voltage').
Of course, some vacuum tubes and solid-state devices have voltage/current characteristic curves that are partly-curved and partly-straight -in these cases Ohm's Law applies only the the straight-line parts of those characteristic curves, but not to the curved parts. Some devices have 'negative' curves, in which current increases when the applied voltage decreases -clearly these do not obey Ohm's Law, either!
Having said that, for non-linear devices, you can use the ratio of voltage to current (= resistance) to find out what the resistance happens to be for any particular ratio of voltage to current -i.e. at a specific point along their graph line.
Is there a 240v 1 hp electric generator?
Since one horsepower is equivalent to just 746 W, it is clear that the motor cannot drive a 3000-W generator! You cannot get more power out of a system than you put into it!
Think it through. A loss is something that goes away, w/o you being able to use it. Losses in electricity is like you putting 10 dollars into your wallet, but when you get to the store there are only 9 left for you to use. No one wants that.
Besides, in electricity losses usually turn into heat, and that heat has to be managed before it gets intense enough to damage something.
There is insufficient information in the question to properly answer it.
You need to specify if the resistors were in series or parallel.
Also, it is incorrect to say "current ... across" - it must be "current ... through".
Assuming that you mean a series circuit then it can be solved:
R(total) = Sum of the resistors in series
R(tot) = 3 x 4 Ohm
= 12 Ohm
Ohm's Law:
V = IR
V = 42 x 12
= 504 Volts
(Note: Because Ohm, Volt and Ampere were named after scientists they are always given capital letters. Ohm not ohm)
