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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 the difference between a complete and incomplete circuit?
In the simplest form; The difference between a complete and incopmlete circuit is... Complete means that electricity CAN and WILL flow through it where as with an incomplete circuit does not have the ability to conduct current is broken... Here is an example. -----/----- Incomplete cicuit, something preventing electricity to flow ----------- complete circuit, electricity can flow.
What is a BTD when dealing with large HP electric AC motors?
BTD stands for bearing temperature detector.
Why DC rating of Relay contacts is lesser than AC rating you need theoretical approach?
100 v DC is not the same as 100v AC the AC will be 141v which can arc over the contact if rated as 100 v DC.
The deal is that when switches open and close they arc for a short period of time. This is the main factor in wearing out the switch. Because AC automatically alternates back and forth, the arc is naturally extinguished faster. The DC, however, sustains the arc until the switch gap is large enough to shut it down. Therefore, the DC ratings must be lower to provide the same switch life and reliability.
What effect if load increase in electrical system?
when load on the electric system increase frequency of the system will decrease resulting in higher intake at powergenerators. If higher intake is not net by powergeneration stations entire power system will collapse. It is called grid failure.
Another AnswerAn increase in load will result in an increase in load current.
A sine wave of 17 volts peak is equivalent to how many volts RMS?
ERMS = 0.707 times Epeak = .707 times 17 volts = 12 volts RMS
Erms = Epeak / Sqrt (2)
(Note I'll be using different notation so, E = V)
The above is derived from using.
v = VMsin ωt ...... Eq1
Where ω = 2πf (angular frequency) & VM is amplitude & π (pi radians)
and
VRMS = √[1/2π ʃ2π v2(ωt) d(ωt)] , Eq2
and the standard trig relationship from your maths text book
Sin2A = ½(1 - cos 2A), which is rewritten by replacing A with ωt, thus
sin2ωt = ½(1 - cos 2ωt) Eq3
Armed with these three equations, lets begin...
substitute v in Eq1 into Eq2
VRMS = √[1/2π ʃ2π vM2 sin2ωt d(ωt)] Eq4
Now apply trig relationship Eq3 to Eq 4 above & rearrange.
VRMS = √[vM2/4π ʃ02π (1 - cos 2ωt) d(ωt)] Eq5
Now take the integral using limits 0 to 2π as shown by ʃ02π .
√{vM2/4π [ωt - ½ sin 2ωt]02π}
continuing...
√{vM2/4π [(2π - 0) - (0 - 0)]}
VM / √2 which is the same as your first responders Epeak / Sqrt (2) , just using different notation.
0.707VM
or
0.707Epeak
What is the purpose of cable select?
Cable Select allows for the faster installation of additional or replacement drives. It does this by allowing the position on the cable itself to determine whether it acts as the Master or the Slave drive on an IDE channel. Thus when replacing a drive or adding a new one, the setting of the other drive is not an issue if it also set up for Cable Select support. Otherwise, one would need to know whether the other drive installed in the system was Master or Slave, so that the corresponding jumpers could be set.
What causes an 02 heater circuit malfunction on a 2000 Maxima SE?
Newer oxygen sensors are heated for accuracy. If the heater element goes bad the oxygen sensor doesn't work and needs to be replaced. If you have an oxygen sensor heater malfunction, it just means that the oxygen sensor has failed.
What is 'non-coincident peak demand' in an electrical system?
Non-Coincident Peak (NCP) is the individual or actual peak demands of each load in an electrical system oftentimes occurring at different hours of the day. It does not necessarily fall during system peak. (This is what i understood about NCP...I gladly welcome corrections)
What is electrical discrimination?
Electrical discrimination is when a smaller circuit breaker (fuse) located closer to an electrical fault, operates before a bigger circuit breaker which is further away from the fault. This then stops disruption to other circuits by knocking out the fuse which not only knocks out the fault, but all the other circuits with no faults on them.
What is the definition of Residual Engineering?
Residual engineering I think is the thought and kinetic process of recycling energy.
Laplace transforms are used in electronics to quickly build a mathematical circuit in the frequency domain (or 's' plane) that can then can be converted quickly into the time domain.
The theory of how this works is still a puzzle to me, but the methods used are straightforward. Simply solve the integral of the function in question multiplied by the exponential function e-st with limits between 0 and infinity.
Difference between gunn diode and pin diode?
gunn diode is transfered electron device & PIN diode is semiconductor device
Using blavier test to check for cable faults?
This is use to locate the ground fault of a single cable. This test is performed with the aid of a low voltage supply with an ammeter or voltmeter. In this test the resistance between one end of the cable C1 and the earth is first measured with the other end, C2 isolated to earth and then with the C2 earthed. Let the two readings be represented by R1 and R2 rep! If r1 and r2 are the conductor resistance of the length of cable at C2 to fault and at C1 to fault rep!, and "r" is the resistance of the fault to earth
Can you use a power supply with more amps and not fry the unit?
you will need to be allot more specific on what you are trying to do here.
what is the difference in amps.
what is the device
Generally speaking it is good practice to only use the power supply that the device is rated for.
the biggest issue you will have is this
Power = voltage * current (simple version)
if the power supply you had was 12v at 1 amps then you ca supply 12Watts of power
if the power supply you had was 12v at 10 amps then you can supply 120Watts of power
Just because you can supply 10 amps, and all you need is one, means your power supply is bigger than it needs to be. The device will draw what it is intended to draw. Just make sure the voltage matches.
This law was stated by Heinrich Friedrich Lenz (1804-1865). The law is stated as: The polarity of induced e.m.f is such that it tends to produce a current which opposes the change in magnetic flux that produces it.
It is the speed you electrical drive device will run when it is just running but has not load.
This would apply to:
a furnace fan motor (or any motor) not connected to the fan
a pump that is running but is not pumping anything
a blender with no mixing container on top
And so on
A load not connected to ground but connected in a feedback circuit is floating load
Which transistor configuration having 180 degree phase shift?
... in CE config.. as Vo=Vcc-Ic Rc nw as Vcc is const. v cn say Vo is directly proportional 2 (const.-Ic Rc) so nw when d base voltage is increased Ib will inc. thus, Ic will inc. cuz Ic=beta Ib thus Ic Rc drop increases... as Vo is prop 2 (const.-Ic Rc) thus, Vo will decrease for inc. in Ic...thus d curve for d +ve half cycle in which Ib is increasing drawn in 180 deg phase showing Vo is dec. n vice versa 4 -ve half cycle...
nw in CC... as d o/p is taken frm emitter... Vo= Ie Re so der's no -ve sign..n for d +ve cycle Ie will incr(dat's leakage current) as der's no-ve sign it'll b in phase wid i/p..hence no phase shift as leakage current doesnt incr. so much thus,d o/p voltage Ie Re doesnt inc much thus, d o/p doesnt amplify much thus dis config knwn as emiter follower...
nw in CB,... d I/P is appiled at emitter n o/p is taken frm collector... so, 4 d +ve half cycle d EB junc will b less FB thus causing dec in Ib n thus, in Ic... so dec in Ic causes inc. in o/p voltage(cuz Vo=const.-Ic Rc)..n during -ve half cycle d junc will b more FB(inc in Ic) so o/p voltage will b decreasing..hence der's no phase shift...
for more info...
cont.
shrey.dhingra51@gmail.com
Can the rpm on a sears 1 hp electric motor be changed?
yes, you can. in A/C motor rps(rev/sec) is N(rps)= f/p where f is the frequency and p is the number of pair poles. By increasing or decreasing the frequency the rps will change accordingly. By having less or more pair poles the rps will be increased or reduced. the more pair poles the lower will be the rps.
What are performance parameters of rectifier?
Rectifiers have two parameters of interest - maximum forward current - and maximum reverse voltage. A rectifier is generally chosen based on these two parameters.
Other parameters include turn-on/turn-off time, forward voltage drop, and capacitance. The importance of these and other parameters depends on the circuit design requirements.
What is wye-delta motor control?
It is a type of starter that allows a motor to be started across the line by starting the motor with a reduced inrush current. The motor is started in a wye configuration until it gets up to speed and then a timer drops the wye contactor out a draws the delta configured contactor in. The motor then operates in a delta wired configuration.
What do i do if my Outboard motor wont go forward but will reverse?
Kind of a broad question: what are you attempting to accomplish? get back to shore? fix the thing? How large is the boat, how large the motor? What materials are at hand to use? If attempting to get to shore and the water is calm, simply go backwards all the way. If not, and such is possible, remove the motor from the transom and clamp it on the side of the boat, you should be able to use reverse to go forward. Really, I think you are going to have to re-write this question.
