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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
How do I figure watts if I know voltage and ohms?
Volts time amps equals watts so watts divided by volts equal amps.
Advantages of current transformer?
A CT allows:
- heavy currents to be measured using conventional ammeters, and
- electrically-isolates the ammeters from high-voltage primary circuits.
What are the capacitor effects on a single phase induction motor?
As anything to do with timing values for an electronic system of controlling a motor. Based on the question, the simple answer is that the capacitor causes a 90 degree lead which allows the motor to have a magnetic shift which causes the motor to start rotation.
5 ohms...
1 kilowatt is equal to how many amperes?
Kilowatts means power P and amperes mean electrical current I. That does not go together. Power is not current. There is nothing equal. 1 kilowatt means 1000 watts. You can make a calculation if you know the voltage V. P = V times I I = P / V = 1000 watts / x volt
What is the difference between kva kw kvarh and kvah?
kVA and kW are similar units of power (kiloVoltAmps and kiloWatt), because a watt is volts times amps.
kVAh (or kWh) (kiloVoltAmphours) is the measure of energy: power times unit of time. It is the standard power measurement used by electricity service utility companies.
If a 1kW electric fire is used for 2 hours, it has used 2kWh of energy. A 2kW fire used for 2 hours or a 1kW fire used for 4 hours uses the same amount of energy, 4kWh.
If your device is a pure resistive load then the ac (alternating current) voltage will be used to force the current through the load with a power factor value of 1 (one) and your kVARh will be zero.
If you have a pure inductive load then the voltage will not immediately be able to push the current through the load due to it's very high initial impedance (similar to inertia with a massive object when you push it) but once the current starts to move (its ac cycle rises from zero) the voltage starts to drop off (its ac cycle falls from 100%).
This effect is called the "phase lag" of an inductive load having a power factor of less than 1 and causes some of the kVA being generated at the power station to be wasted - the lower the power factor value, the more the % of kVA that is being wasted. The unused/useless % of kVA must still be generated by the electricity service utility company, even though it is not used, so they have to charge for it as kVARh (kiloVoltAmpsReactivehours).
Which circuit used to convert a sine wave to a square wave?
Though it is not possible to get a mathematically perfect square wave from a sine wave, it is possible to get a reasonably close square wave from a sine wave. A clipper circuit is one which clips off the top of a sine wave thus giving it a flat top. Clipper circuits find their applications in electronics but not in electrical engineering (that deals with bulk of the power that we use, both at home and in industry).
You can also use a comparator, detecting the zero transitions, and producing a digital output which will be close to a square wave. Squareness will be dependent on symmetry, of course.
What is the relation between voltage and speed?
I=vnqA
If what you're asking refers to the average speed at which a charged particle, such as an electron, travels down a conductor when a voltage is applied you can use the formula above, where I is the current, v is the average velocity of the charged particle, n is the number of those particles per square metre of the conductor, q is the charge of the particle and A is the cross-sectional area of the conductor.
Of course I=V/R
Where V is the voltage and R is the resistance of the circuit.
So a direct relationship would look like
V/R=vnqA
V=RvnqA
How does nuclear fuel generate electricity?
It cannot do it the direct way. Nuclear energy makes heat and this heat can be used do heat water that drives normal turbines that make electricity.
Most commonly, nuclear energy is used to boil water and produce high pressure steam. The steam is then used to turn a turbine, which turns a generator which produces electricity.
What is meant load dispatch center?
Load dispatch can refer to a trucking company that finds truck drivers for loads of product. When the load is dispatched, the driver picks the load up and takes it to its delivery destination.
What is mean KVA Rating of transformer?
copper loss is directly propostional to I (AMPERE) and iron loss directly propostional to V (VOLTAGE) then total losses is equal to volt ampere hence the rating of transformer in KVA.
SULTAN
What happens if load is greater than output power?
For AC system speed of generator will be decreased and then frequency decrease, if there is no trip the motor load will be automaticaly reduced as Load Power = torque x speed and speed of motor vary acc to frequency. Finally the motor will be run at new lower speed that load = power generation. The other effect is voltage in the system will be decreased and result of lower load consumption
What is the definition of a steel wired armoured cable in electrical engineering?
Underground cables are 'armoured' in order to protect them against mechanical damage. This armour takes either of two forms: (1) steel tape, or (2) wire. Wire armour tends to be used on cables with a larger diameter, as it makes them more flexible compared to cables with tape armour.
In both cases, the armour is spiral-wound towards the outer part of the cable along its length and is, itself, protected with a hessian or plastic outer layer.
3 phase 220 volts to 1 phase 220 volts?
No, a 230V supply is normally single phase, 50 Hz. It is the most common supply used in homes and offices in Europe and many other areas of the world.
For more information see the answers to the Related Questions shown below.
Another View
In Europe, low voltage is distributed as three-phase, four-wire, supply system having a nominal line voltage of 400 V (line-to-line) and a nominal phase voltage of 230 V (line-to-neutral). So, yes, you could describe 230 V as being a 'three-phase' voltage.
Most residences are provided with a single-phase supply, which means that each home is connected between one of the three line conductors and the neutral conductor of a three-phase system. In some European countries, such as Cyprus, it is common for residences to have three-phase supplies, with the various circuits within the home being roughly-evenly distributed between each of the three lines and the neutral.
What is the difference in single phase and dual phase?
single phase means that there is only 1 live core in the cable (+) . so dual phase means there are 2 live cores in the cable. this is used to supply different parts of a device where needed. although three phase cable sometimes used to boost power to 400 v
Further answer
Actually it's not correct to say "boost power to 400 v". Power is measured in watts, not volts, although I agree the voltage of three-phase, at least in the UK, is 400v (I don't know about the US - they have lower domestic volatges than the UK anyway)
CommentIf, by 'dual phase', you actually mean 'two phase', then this electrical system is quite rare, and consists of two phase voltages displaced by 90 degrees, as opposed to a three-phase system in which the phase voltages are displaced by 120 degrees.
What is the difference between active load and passive load?
Passive Load is Load comprising of Passive Components
Active Load is the Load comprising of Active Components
In Test Boards its better to use Active Loads, If you are concerned about Temperature Variations during characterisation
There's is five different kind;
Audio, Radio, Microwave, Logic and Arbitrary.
Condition of three phase in which there is no need of neutral?
A delta-connected system is described as being a three-phase, three-wire, system, and doesn't have a neutral. But a balanced star (wye) connected load (e.g. a three-phase induction motor) doesn't actually require a neutral.
What benefit does electric power have on factories?
To see this simply go to any old factory that was around before electric motors. You will see the reminants of an intricate power delivery system to drive rotating equipment. Long axles ran across the roof of the building, with power take off pullies every few feet. Each machine was powered from one of these pullies, so each machine had a belt running to it from the cieling. To stop and start an individual machine a clutch was needed, as stopping the steam engine or whatever else powered the whole plant was not an option. All the rotating equipment posed a huge safety hazard, and I'm willing to bet arms were lost to those belts. If a belt came off the pulley the axle had to be stopped to (safely) get that machine on-line again. Electricity de-centralized this power system. Instead of one big engine powering everything, small motors powered individual tools. The need for all the belts and axles was eliminated. Machines could be run and repaired independently. Machines could be stopped and started with a cheap switch, not an expensive clutch. Also, electric lighting was safer and brighter than gas. IIRC fires were serious problems in plants that produced lint or dust because of the explosion hazard.
Why does voltage remain constant in the reverse breakdown region in a zener diode?
This space is for answering "http://wiki.answers.com/Q/Why_does_voltage_remain_constant_in_the_reverse_breakdown_region_in_a_zener_diode" Why does voltage remain constant in the reverse breakdown region in a zener diode?
How differential generator is used for electric arc welding process?
in welding sometimes your electrode got stuck to your work piece so a very high current would flow and no voltage at generator teminals. only a small voltage will produce in the armature due the residual magnetism in the machine itself.
The only type dc machine that can operate satifactorily in this situation is a shunt connected dc genrator.
This type of generator can run and exceed it full load current. if it allows to run beyond its rated load or its loads becomes zero ohms, then this machine is able to take up that load.(short ccit condition)
So in differential generator to make it use for electric arc welding, just simply short out the series winding so there would be no flux induced or produced in it. only the current flows through the shunt winding.This time the generator is now running as a normal shunt connected dc generator. voltage output can be adjusted/varied by means of rheostat connected in series with it and armature.
Can you run a star motor in delta?
Delta motors should have more starting current than Wye (Star) motors because Delta motors have two windings to take current per phase -- they are wired Phase to Phase. Star motors have only one winding per phase -- they are wired Phase to Neutral.
How do you Calculate elevator counterweight weight?
Elevator Counterweight = Half of Elevator Maximum Capacity + Cab Weight
For eg: 10passenger Elevator = 10*80 = 800Kgs
Counter Weight is 800/2 = 400Kgs + Cab Weight
This is just to create a imbalance between Elevator cab and counterweight in order to save power in the drive.
