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The volt ampere is a measurement of apparent power, while the watt is a measurement of true power. Apparent power is simply the product of voltage and current; the output of a transformer, therefore, is the product of its rated secondary voltage and its rated secondary current -i.e. the apparent power of the transformer. The power supplied, in watts, is determined by the power factor of the load, so there is little point in rating a transformer in watts, as the designer has no means of knowing the power factor of the load it is to supply.

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How the motor rating will be calculated?

thats stupid it dont make sense im not trying to be mean though


Who invented the generator?

The electric generator was first made in 1790 by a man named Aloisio Galvani. Over the years, scientists improved the practical and theoretical parts of the equipment. In 1831, another man (named Michael Faraday), discovered the operating principal of electromagnetic generators. The principle is now called Faraday's Law. The first workable units though for generating power were created by Nikola Tesla. He is created with the creation of alternating current, which requires a method of creation. He is also credited with the creation of the motor which is very similar in construction to the generator.


How long for a cable to heat up at maximum current rating?

It depends on the surround material, temperature, type of cable, and what you mean by "maximum current rating". Typically a maximum load current rating will be specified, such as 15A; this means you can push 15A through that cable nonstop without damaging it (it won't overheat). You might have a short time rating as well, such as a 4 hour rating, where the cable can handle runing 22A for 4 hours if the surrounding temperature is kept to some value, though this may slightly degrade the insulation. There's also a fusing current rating for many cables. At this current, the cable will eventually melt (like a fuse).


Why is a synchronous machine not self starting?

A synchronous generator generally requires DC power supplied to the rotor winding to make it into an electromagnet. As the rotor spins, a voltage will be induced in the stator windings (the stationary windings). A synchronous generator needs something to supply this initial DC power to the rotor, so it may be deemed to not be "self starting". "Self starting" may have several different interpretations, though. A "black start" generator could be deemed as being self starting, even though this initial power is (usually) supplied by a set of batteries. Many generators pull this power from the power grid, so if the grid is not energized (black start conditions), these generators cannot start until at least part of the power grid is put back in service with another generator.


Is surge current the same as short circuit current?

Not usually, but it may depend on the context. For instance, surge current might be used for a generator that is going to start a motor. Motors draw high current as they start, then the current drops to a normal level, called RLA, or running load amps. Generators have a watt rating for continuous operation called running watts, but they also have a 'surge' rating. You might see a generator listed as a '6000/5200 watt. The 6000 watts is the 'surge' rating. This means the generator can supply 6000 watts for a few seconds, such as might be needed to start a motor, but cannot supply more than 5200 watts continuously. Short circuit current on the other hand simply means how many amps will flow instantaneously if you drop a wrench across the two wires! For a normal utility power service, the short circuit current, also called fault current, can be several tens of thousands of amps, even though the main breaker is only a couple hundred amps.

Related Questions

Why generating station capacity mentioned in KW even though alternator rating is in KVA?

In generator station the power which produced is real power the real power to me mentioned in its's factor so it is mentioned as KW or MW. In transformer there is no effect of change the power factor (ie:cos,phi) and the power which transfer do not changes its frequency. so, in Transformer and generator it is mentioned as KVA.


Are vandergraff generators considered the best generator on the market today?

These generators aren't as efficient as Windhurst machines, for instance. They are a good value, though.


Where can I get power generator home about in Alaska?

ElectricGeneratorsDirect.com and 360Generators.com both sell generators in Alaska. Home Depot also sells generators in Alaska, though they do not offer home delivery.


Is the space marine game a 15?

in the uk yes though in the us it does not have a rating yet (rating pending)


How can magneto hydrodynamic generators can convert solar heat?

They can't. You can use solar heat to drive the unit though.


Is there a zara in Atlantic station?

Nope, there is one in Buckhead though.


How do Honda and Cummings power generation technology compare?

Honda generators are obviously going to be of better quality and easier to use than Cummings generators, mainly because of the types of parts used. They would be more expensive though.


Can you have a docking station in the bathroom?

Yes, if there is an electrical outlet, you can have an iPod docking station in the bathroom (though not recommended due to the water that could damage the iPod and/or the docking station).


Does piccadilly circus have a lift?

The Underground Station does not have a lift - it has escalators though.


Should the nuclear waste storage facilities be located where energy is generated?

You used the word "should" there, which means the answer is subject to debate. In principle, there's no technically compelling reason the waste site has to be near the generating site, though it does simplify security to some extent (the generating site has to be secure anyway, and it eliminates transportation issues). Politically, however... most places don't really want to feel like they're someplace else's dumping ground, so the citizens may be reluctant to accept a distant location's waste. If the generating station is already generating power that's mainly being sent somewhere else, then storing the waste there also is adding insult to injury.


Can the cash generating process for a firm be continuous even though cash flow can be sporadic?

Yes. Rentals of skis is an example.


Can you get the Blockland key for free?

You can but it's illegal. They are done through keygens, or key generators. Most of them have viruses though, and if caught you can be fined steeply.