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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
Overfluxing is when a magnetic flux density increases to very high levels. This can cause excessive currents inside transformers and becomes very dangerous.
Class B circuit fire alarms are much louder and powerful than class A's. They are only recommended for people with sever hearing loss.
What is the average value of an ac voltage that has a maximum peak voltage of 80 vac?
To get the average:
Volts avg=0.637 X Vp (peak)
0.637 X 80 Vp = 50.96 Vavg
To get rms (root mean square):
Volts rms = 0.707 X Vp (peak)
0.707 X 80 Vp = 56.56 Vrms
CommentIt should be pointed out that the average value, described above, is for half a cycle. The average for a complete cycle is zero.
What is an arc voltage in a circuit breaker?
ARC VOLTAGE is the voltage that appears across the contacts of circuit breaker during the arcing period, during which the current flow is maintained in the form of an arc. The arc voltage value is low except for the point at which the current reaches zero when the arc voltage rises rapidly to a peak value.
What are the Advantage of three phase motors over single phase?
A 3 phase system needs only to use 3 or 4 conductors, as against 6 conductors if it were 3, single phase conductors
The amount of copper used in a 3 phase is much less than what would be needed in a single phase system carrying the same current, this reduction in copper allows for weight reduction and cost savings.
The power losses in a 3 phase system are much less than in a single phase system.
What size ground wire for 700A?
As per NEC for 700A you can use a min. of 1/0 AWG(50mm2) copper or 3/0AWG (95mm2) aluminum ground cable. hope this answer your question. Hattab
There are two types of lamps the tungsten halogen lamps and incandescent lamps. Tungsten Halogen Lamps are similar to incandescent lamps and produce light in the same manner from a tungsten filament; however the bulb contains a halogen gas (bromine or iodine) which is active in controlling tungsten evaporation, whereas the incandescent lamp suppresses tungsten evaporation.
How do you calculate resistivity of copper wire?
(rho) or resistivity of a "wire" is calculated using this formule:
rho = Resistance x Area / length of material
the resistivity of copper is 1.7 x 10 -8 ohm/m
Resistivity is measured in ohm metres, NOT ohms per metre!
Function of molded case circuit breaker?
== == == == == == To open a circuit during an overcurrent event, thus protecting the cabling and devices connected to it.
How does frequency modulation work?
Frequency modulation (FM) works by taking a signal, such as an audio signal, and using it to modulate a higher frequency (Radio Frequency, RF) carrier. This modulation causes the RF to shift up and down in frequency. The RF remains relatively constant in amplitude, and its shifting frequency represents the original signal.
Contrast this with Amplitude Modulation (AM) where the RF is relatively constant in frequency, but its amplitude represents the original signal.
In order to recover the original signal in an FM system, the receiver must demodulate the signal by measuring the time between successive waves of the RF. In a typical broadcast band system, limitations in the the design requirements for tuning the modulated carrier and for demodulating the original signal force the tuning and demodulation to be done in different stages. Using a process known as superhetrodyning, the tuner amplifies the RF with a broad-band amplifier and mixes the RF with a local oscillator (LO) frequency, converting the RF into an intermediate frequency (IF), typically 10.7 MHz. It then passes the still modulated IF (or shifted RF) into a sharp band-pass filter, the IF stage, and removes the interference of other stations from the IF signal. It then demodulates the original signal from the IF signal.
Often, the original signal contains encoded information, such as a stereo subcarrier, which is subsequently demodulated and demultiplexed in order to recover the stereo signal. The question, however, asked about frequency modulation, so the answer stops here. If further detail is required, either add it by refining the answer, or comment on the question, and I or someone will refine the answer.
An induction relay works only with alternating current. It consists of an electromagnetic system which operates on a moving conductor, generally in the form of a disc or cup, and functions through the interaction of electromagnetic fluxes with the parasitic Fault currents which are induced in the rotor by these fluxes. These two fluxes, which are mutually displaced both in angle and in position, produce a torque that can be expressed by
T= Κ1.Φ1.Φ2 .sin θ,
Where Φ1 and Φ2 are the interacting fluxes and θ is the phase angle between Φ1 and Φ2. It should be noted that the torque is a maximum when the fluxes are out of phase by 90º, and zero when they are in phase.
How can you tell from the IMEI number who is the Vendor?
I recently needed also to match IMEI with the vendor and device type. I found the following webpage where you can enter IMEI and get the device and vendor details at nobbi.com: http://www.nobbi.com/tacquery.php The only disadvantage is that if you need to match lets say more then 20 devices then you have to enter each one by one. Otherwise it is a great site. Good luck!
What is Lightning impulse withstand voltage?
The instantaneous voltage rating of a given insulation sytem. In the case of a lightning strike, it is very high voltage but only for a split second. The insulation is designed to handle this rated voltage for a split second without damage to the apparatus. Any longer, and damage would result.
Is it possible to connect a generator of 100MW in parallel to that of 50MW?
yes it is just hook it up and go you will need to check your calcs as you will increase your amperage. while not often done I have done this before.
The lap winding is used in dc generators designed for high-current application
How much energy does it need to build a windmill?
1,123,123,123,211,125,125,125,123,123,123,114yes i do
What is the definition of commutator?
A commutator is an electrical switch that periodically reverses the current direction in an electric motor or electrical generator. A commutator is a common feature of direct current rotating machines.
Where can wind energy be used?
anywhere, smart one
That's right, anywhere. Small, efficient wind generators have now been designed that can be placed nearly anywhere the wind blows. This includes homesteads, schools, green houses, city houses, boats, at campsites, etc. So, not only can you use the energy produced from wind everywhere we use electricity now, we can also generate it at the site of consumption.
How do you calculate the peak-to-peak value of a sine wave?
All AC voltages and currents are quoted as root-mean-square (rms) values where, for a sinusoidal waveform, the rms value is 0.707 Vmax or 0.707 Imax.
From this, you can determine the value of the amplitude Vmax or Imax:
Vmax = Vrms/0.707 or Imax = Irms/0.707
Once you know the value of the amplitude (Vmax or Imax), simply double it to determine the peak-to-peak value.
Why don't equipotential lines cross?
If this means voltage potential it is a conservative force so it is path independant, much like gravity, it doesn't matter how somthing got to where it is it will still have the same potential at that height. So if it had two different potential lines crossing it would be much like an object having different potential energies at one point in space. This is impossible.
What is epoxy resin cast transformer?
The epoxy resin cast transformer steps up or steps down voltage. The epoxy resin cast transformer generally generate low noise and are very cost efficient. They are also resistant to failure as compared to the other types of transformers.
What approximate percentage of energy is converted to heat in average incondescent light bulb?
95% , since they are only approximately 5% efficient
What is neutral shift how is it neccesarry?
Neutral shift describes the phenomenon that happens when an AC motor drive shifts the neutral point of the motor. This is important because it can significantly interfere with the motor's ability to function if proper precautions aren't taken care of.
How does humidity effect power lines?
Electricity has the ability to arc or jump up to almost 20 feet. When power lines have a high amount of voltage running through them, and the humidity is high, the electricity can arc even more that 20 feet.
