All Questions
Tagged with electricity electrical-engineering
69
questions
51
votes
8
answers
207k
views
Difference between live and neutral wires
In domestic electrical circuits, there are 3 wires - live, earth and neutral. What is the difference between the live and neutral wires?
As there is AC supply, it means that there are no fixed ...
1
vote
2
answers
2k
views
Flow of charges in two different materials
Consider two cylindrical conductor rods: one copper rod and one aluminium rod. The rods contact at a circular face, aligned coaxially.
Their exterior circular faces are connected to some DC voltage. ...
- 31
0
votes
1
answer
1k
views
Why do electrical storms cause metal objects to vibrate?
I am curious about the vibration of metal objects as a sign of an impending lightening strike. This is apparently a common occurrence; so much so that a quick google search will yield many pages ...
- 3
2
votes
2
answers
339
views
How do you model the resistance across a symmetric sheet of plastic, streched (think ceran wrap) between a circular anode and cathode?
Here is the problem. You need to model the resistance across a circular sheet of polypropylene (plastic). The resistivity of polypropylene is 1E15 Ohms per meter. The expression for resistance on a ...
- 170
4
votes
3
answers
5k
views
Why is the electric field highest in regions of highest resistance?
I know Kirchhoff's law and that current must be constant. But what exactly is the phenomenon, from first principles, that causes the electric field to be stronger in a region with lower carrier ...
- 310
-1
votes
1
answer
2k
views
What device is best to prevent electric motors from burning out? [closed]
Is there any equipment to prevent electric motors from burning out? I have researched about Transient voltage surge suppressor TVSS and also Surge protection device. Can this help?
- 1
0
votes
1
answer
368
views
Can incandescent light bulb can be brighter if fixed power?
I found that luminous efficacy of 60 W tungsten incandescent bulb is 14.5 lm/W.
Is this value defined by design details listed above or it depends on something else too?
Can we design 60 W tungsten ...
- 1,732
0
votes
1
answer
285
views
How do cathode ray tubes (CRT) synthesize colours?
I just read about how LCD displays were based only on black&white contrasts, and only colour filters on each subpixel generated the colour of a pixel. However, how does that happen for a CRT?
Is ...
- 995
0
votes
1
answer
59
views
Applying more current? [closed]
An electric motor draws 20 Amps, when at maximum load of x.
Can that value of current be applied even if the load was ten times less than x from a certain power source?
- 1,110
0
votes
1
answer
467
views
Magnetic core, and a DC solenoid
A DC solenoid creates a magnetic field B.
A highly permeability magnetic core is added to solenoid to increase B.
Now, there is change in flux, due to the increase in magnetic field. What would be ...
- 1,110
-5
votes
1
answer
407
views
traditional transformer design improvement [closed]
The traditional tranformers suffer a lot of losses in various forms, some of them are as follows :
1. Flux leakage
2. Eddy currents
3. Hysteresis
Figure :
But as we are taught induction we come ...
- 5,481
0
votes
1
answer
62
views
How to produce a bigger rotational velocity from two rotational velocities?
If I have two electronic motors, both running at the same voltage and current, delivering the same rotational velocity, how could I produce a bigger rotational velocity from them?
user29727
0
votes
1
answer
584
views
Current in AC circuit
The problem is to find the current on the capacitor. $I''$ should be correct, but I don't know how to construct the formula for $I'$.
I managed to get the value for $I_c$ using Thevenin and Norton ...
5
votes
2
answers
29k
views
How does current flow from the emitter, through the base and to the collector in a NPN transistor?
So, I understand that for a NPN transistor to work the emitter-base junction needs to be forward biased and the collector-base junction needs to be reverse biased. I understand how current flows from ...
- 59
17
votes
6
answers
19k
views
Why is electrical energy so difficult to store?
Does anyone know a general answer to these questions? (I've asked them together because they're all pretty related, it seems.)
Why is it that we find electrical energy so difficult to store? Do we ...
- 1,657
3
votes
3
answers
186
views
whether electricity that comes in our home comes directly after generated or first stored and then distributed
Please give answer that, whether electricity in our home comes directly after it is generated e.g. at a dam or nuclear plant or first it is stored somewhere and then distributed as it is needed.
2
votes
1
answer
946
views
Electrical flow in a simple parallel circuit
I'm having trouble understanding something in one of my text books:
Let’s have a look at the implications of each circuit configuration.
Figure 3.13 shows the Conventional representation of a ...
- 207
1
vote
3
answers
15k
views
Calculating time for a fully charged UPS
I have a UPS of 1000 Volts connected with 2 batteries each of 150 Amp. How much time it will take to consume the whole UPS (after fully charged) when a device of 1Amp is getting electricity form that ...
- 149
5
votes
3
answers
12k
views
Why and how exactly is electric motor torque limited?
Inspired by this question and specifically this answer to it.
From my experience there's always some very specific limit to how much torque an electric motor can output. For example, an electric ...
- 831