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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
What is a short circuit stub matching?
short circuited stub matching network is a s/c length of transmission line is added in parallel to the main line (physically perpendicular) at the precise location so that its reflected wave exactly cancels out the reflected wave from the load. then all the power is delivered to the load. (since it can not be absorbed by the purely reactive matching network) it thus provides a "perfect Match' at the design frequency and results in more efficient use of the power.
How is a three phase agricultural motor used when there is no power supply?
With no three phase power supply you can't use a three phase motor of any kind at all!
Why is a thermal switch often included on the control circuit for a glow-coil pilot burner ignition?
Thermal switch is to cut off the pilot ignition circuit when the heater temperature is beyond a set temperature. The thermal switch limits the temperature and protects the heaters
What is the difference between VT and PT transformer?
Both are same.
AnswerA 'PT' is a 'potential transformer', the preferred term in North America, for what is termed a 'VT', or 'voltage transformer', in Britain. Two names for exactly the same instrument transformer.
How many watts does an electric heater use?
An electric heater is an electric appliance that convert electrical energy in to heat. Working principle of an electric heater as per "Joule heating theory"
When electric current passes through a resistor that electric energy convert to heat (best and simple example is a spring type heating element).
When Voltage applied both end of a wire/spring type Resistance wire, voltage flow and this voltage help that wire to heat up and convert in to heat. A Resistance wire quality, length & thickness depend how many time heat spread and resist with that heat.
K.watt/ Watt = Applied voltage x Ampere.
Many quality and types of electric heating elements are there depend upon purpose of use. Few best heating elements known as Kanthal wire, Nicrome wire, Ureka wire, Super Kanthal, Silicon Carbide heating elements etc.
What is principle of autotransformer?
to step up or step down high voltage
AnswerThe principle is that of electromagnetism.An auto transformer has only one winding which has (usually) one tap on it.
If a voltage is applied across the whole winding, and connections are made between one end and the tap, a lower voltage is available on those connections.
The magnitude of that voltage has a ratio to the overall applied voltage as the ratio of the number of turns across which the voltage is taken, to the total number of turns.
Or, if a voltage is applied between one end of the winding and the tap, then an increased voltage may be obtained across the whole winding.
The ratio of the two voltages being the same as the ratio between the number ..... but I'm sure you can guess the rest.
How is University of Hertfordshire ranked in the World University Ranking?
Its poor.....Its overall ranking is around 60-70.....It may vary according to the subjects..
How many times do you have to wrap copper wires in a coil to get at least 120 Volts?
That question is very hard to answer, in fact it is impossible to give you a short answer because there are whole books written about "How to generate electricity". To give you just a quick idea, you would need to make a whole lot more than just one big coil of wire. You would need a workshop and lots of tools to be able to make an electrical machine such as a generator to produce DC (Direct Current) or an alternator to make Altenating Current (AC).
Those machines must have lots of big metal parts with heavy copper wire windings and lots more pieces.
Apart from that, you would also need some sort of engine to turn the generator or alternator fast enough to make the power you want to produce. Why not go to your local library or a bookshop to read some books about Electrical Engineering? Look up "alternators" and "transformers" in the book index to find the right books to read. There is an answer on how to make an electro-magnet. You can read it if you click on the link to the Related Question shown below.
What supplies electric pressure in an automotive circuit?
The battery and the alternator.
The "electrical pressure" probably refers to the voltage. This is usually provided by a battery. The battery is recharged by the engine when it is running.
What does grounding a connector mean?
"Grounding a connector" means you join a connector in a circuit to another point in the circuit that is definitely at ground potential.
This is done mainly when testing a circuit, to be sure that a particular point in that circuit really is at ground potential if you are not certain that it is already.
Alternatively, you could be doing a test to temporarily ground a connector that is not normally at ground potential, to see what effect doing the test has on the behavior of the circuit.
== == Add a capacitor or a synchronous motor or a phase advancer to the transmission line so that it can nullify the effect of inductive reactance since the above elements gives capacitive reactance. Doing this also improves the power factor.
It is a the current drawn by the application that is connected to the power source
Uses of Electrical joints and splices?
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How do you get two different voltages using the delta - star connection?
A star connection is where the three phase nonpolarities are tied to a single point, and very often grounded. A delta connection is where the nonpolarity of one phase is tied to the polarity of another phase, forming a greek delta shape. If measuring from polarity to nonpolarity on a single phase, in the star formation you are looking at L-N voltages; in the delta connection, you are looking at L-L voltages (L-N voltages * square root of three).
Possibly loose belt or bad bearing(s). Check tension first.
What are the advantages of volt ohm meter?
If there is a meter that shows volt and ohms then it is showing you the amount of voltage and resistance there is. However these meters are two separate devices with different uses.
AnswerA 'volt ohmmeter' ('VOM') is a term used in North America to describe what is known, elsewhere, as a 'multimeter'. A multimeter combines the functions of a.c. and d.c. voltmeter, ammeter, and ohmmeter. The advantage of a multimeter is that it avoids the necessity of having to carry about six separate measuring instruments.
What voltage is the power supply for a quest 2wire gateway model 2700HG-D?
The 2wire 2700 and 2701 models both use a 5.1 volt power supply rated 2 or 2.2 amps
AC/DC plays hardcore punk but call them rock and roll that's what they like to be called. They aren't metal.
Michael Faraday discovered the operating principle of electromagnetic generators.
Who measure of charge differential voltage?
Any one using a voltage test instrument can measure charge differential voltage.
Why you need to connect resistor in series for the practical voltage source?
A resistor is connected in series with a practical voltage source in order to determine the current produced by the source.
The starter is sized by amperage of the motor. The first thing that has to be done is find the the current by using this formula for amperage when the HP is known. I = HP x 746/1.73 x E x %eff x pf.
A standard motor's efficiency between 5 to 100 HP is .84 to .91.
A standard motor's power factor between 10 to 100 HP is .86 to .92.
Amps = 5 x 746 = 3730/1.73 x 208 = 3730/360 x .84 x .84 = 3730/ 254 = 14.68 amps
A three phase size 1 magnetic starter is rated for 27 amps and can be used up to 7.5 HP.
If the voltage was 460 to 575 a size 0 could be used.
Why are series circuits sometimes called current coupled or daisy chain coupled?
daisy chains are strings or loops of actual growing daisy flowers. To make a ckain, you pluck a blossom with about 2" of stem. With your fingernail, make a slit along the stem so that you can slide the stem of the second daisy through it..DON'T PUSH IT ALL THE WAY THROUGH. When the blossom of the second daisy reaches the slit in the first stem,STOP!!
Now,holding the 2 stems together, slit the second stem just like the first and insert a third daisy stem into this slit.
Now,holding the three daisies in a chain together,make a slit and insert a fourth stem.
continue until your daisy chain is as long as you wa-ooops- one of the slits in the chain etended to its end and broke that segment.
you did all that work before and after the break,but the daisy needs fixing.
my grandmother taught me how to daisychain.
Why a circuit is protected by a circuit breaker?
1. protection against fire hazard from a short-circuit. A short-circuit can be caused by a loose wire, faulty insulation, or faulty wiring. A short-circuit will cause the wires to heat up rapidly, presenting a fire hazard.
2. protection against circuit overloading. Too much current in a wire caused by overloading (plugging in too many high-power appliances, for example) can cause overheating, presenting a fire hazard. Most circuit breakers have a "slow-blow" mode that breaks the circuit if overload continues for too long.
3. on grounded appliances (which have the third prong on the plug), the ground is connected to all exposed conductive material on the appliance. In the event that a loose wire contacts the exposed metal, a short-circuit will occur, and the power will be cut. This protects against accidental electrocution.
Circuit breakers do not protect against fire hazards from inferior gauge of wire, glow-faults, or arc-faults. Most do not protect against electrocution hazards from ground-faults (although some do).
What is the voltage rating of lamps on a parallel circuit with a 12 volt battery?
If the lamps (the technical term for light bulbs) are the "correct" ones, the 12 volt battery is all there is and all the lamps are connected in parallel, the lamps are rated at 12 volts. There are a flock of assumptions, but why not pick an easy example to make a case? The average vehicle has a 12 volt electrical system. Car people throw that number around all the time. But the actual voltage on the power buss when the engine is running is in excess of 13 volts because of the alternator that keeps the battery pumped up and runs the electrics. All the lights on the rig (and they're all connected in parallel) are run off the 12 volt buss. Ask an auto person what a light bult for a car is rated at and the answer may very well be "12 volts" (the normal expression of the buss voltage). Could it be said the lights are rated at 13 volts (or 14 volts) because that's the actual working voltage of the system with the engine running? Sure. Why not. Whatever works. The lights will work at a higher voltage (15 volts) , but they will be far more susceptable to damage by vibration and shock. And they will certainly have a shorter life if the voltage is ramped up. Keep it simple and say that lamps designed to work in a 12 volt system are rated at 12 volts. Don't go into an auto parts store and ask for a lamp rated at 14 volts. You'll probably just confuse the parts helper. The folks who make the light bulbs know the drill, know the normal range of voltages over which the light will be working. They'll optimize their designs to produce fairly priced but well-performing pieces that stand up nicely over a modest range of voltages. And that includes some voltages a bit above the actual "rating" of the lamp.
