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Type: Posts; User: julian403

1. ## Thread: zero magnetic flux in the transformer core when there is a short circuit in the secondary

by julian403
Replies
1
Views
1,641

### zero magnetic flux in the transformer core when there is a short circuit in the secondary

Hello All.

if the secondary current of the transformer produces a current flow that opposes the initial field (lenz's law). Why is not a zero magnetic flux when there is a short circuit in the...
2. ## Thread: Laplace operator

by julian403
Replies
5
Views
1,450

### I think laplacian talk about the causes of the...

I think laplacian talk about the causes of the vectors and scalar field. In that case it says that the cause of the gavitational potential is the mass density. For the

{\nabla}^{2} V =...
3. ## Thread: Laplace operator

by julian403
Replies
5
Views
1,450

### View Post

with the expresión

\nabla (\nabla .A) - \nabla \times \nabla \times A

the first term of the equation is the gradient of the divergence. So it is a vector whose magnitude is the rate of...
4. ## Thread: Laplace operator

by julian403
Replies
5
Views
1,450

### Laplace operator

I am studying electromagnetism but there is a concept that can not lead to the interpretation and it's Laplace operator o laplacian.

{\nabla}^{2} A = \nabla (\nabla . A)- \nabla \times \nabla A ...
5. ## Thread: Unit Jy

by julian403
Replies
4
Views
883

### So, a [Jy] it's one watts in one metter square...

So, a [Jy] it's one watts in one metter square for a frecuency of one hertz. If we have a radiation of 250 [Hz] which have 2.50 [W/m^2], so

\frac{2.50}{250}=0.01 [Jy]

Thats correct?
6. ## Thread: Unit Jy

by julian403
Replies
4
Views
883

### Unit Jy

The Jansky unit. It's a unit for intensity ? or for energy? Because Jy = W {m}^{-2} {Hz}^{-1} = W {m}^{-2} T
7. ## Thread: The beggining of the planet orbit

by julian403
Replies
2
Views
878

### Thanks. And Assuming that the primitive planet...

Thanks. And Assuming that the primitive planet got an m mass and it's descibing an orbit. If in the future the planet get more mass. It will take a lower orbit or may increase the tangential velocity...
8. ## Thread: The beggining of the planet orbit

by julian403
Replies
2
Views
878

### The beggining of the planet orbit

Why the planets describe an orbit around the star? Yes, I know gravitational force acts as centripetal force. And there is

\dst {m}_{p} \frac{{v}^{2}}{r} = G \frac{{m}_{p}{m}_{s}}{{r}^{2}} ...
9. ## Thread: Definitions of volt using SI's fundamental magnitude

by julian403
Replies
28
Views
1,734

### So, the definition of volt is still the derivate...

So, the definition of volt is still the derivate of amperio. But, Why using a new patron like Josephson junction will changes some value of SI, like {\mu}_{0}
10. ## Thread: Definitions of volt using SI's fundamental magnitude

by julian403
Replies
28
Views
1,734

### whay do you mean with it's now defined as...

whay do you mean with it's now defined as traceable to frequency.
11. ## Thread: Definitions of volt using SI's fundamental magnitude

by julian403
Replies
28
Views
1,734

### Thanks. And other question. Why is define like...

Thanks. And other question. Why is define like fundamental the current and not the carge? I think that is practical way. It's really dificult measure charge?
12. ## Thread: Definitions of volt using SI's fundamental magnitude

by julian403
Replies
28
Views
1,734

### Definitions of volt using SI's fundamental magnitude

I need help with the definition of volts. We know that the ampere is the unique electric fundamental magnitude in SI system. And It's define like:

So, how can we define volts? Becuase we...
13. ## Thread: Average, apparent and real power. I'am confused

by julian403
Replies
4
Views
1,321

### I read the page. \dst {W}_{average} =...

I read the page.

\dst {W}_{average} = {V}_{rms}{I}_{rms}

I can measure the \dst {W}_{average} measuring voltage and current with the multimeter because this are rms. But in this case it would...
14. ## Thread: Average, apparent and real power. I'am confused

by julian403
Replies
4
Views
1,321

### Average, apparent and real power. I'am confused

the average power known as rms is the power used in an interval of times that it consume the same power as a continuous signal.

{P}_{rms} = \frac{{V}_{p}}{\sqrt{2}}\frac{{I}_{p}}{\sqrt{2}}= VI ...

by julian403
Replies
5
Views
967

thanks
16. ## Thread: Electric arc

by julian403
Replies
5
Views
967

### So, suppose that average distances of the clouds...

So, suppose that average distances of the clouds to land is 2000 meter, with it we can calculate the diferential of potential of a ray.

\dst 3 [ \frac{MV}{m }] *2000 [m] = 6 [GV]

And,...
17. ## Thread: Electric arc

by julian403
Replies
5
Views
967

### Electric arc

An electric arc is generate when an electric field exceeds the dielectric strenght of the medium? For example if i wanna make an electric arc I must put 30 [KV] in one centimeter? In the air of...
18. ## Thread: Outside magnetic field for Solenoid using Ampere's law

by julian403
Replies
0
Views
1,006

### Outside magnetic field for Solenoid using Ampere's law

Using Ampere's law for a solenoid, We can see here Solenoid - Wikipedia, the free encyclopedia that the magnetic field it's

216

\oint \vec{B} d\vec{l}={\int}_{A}^{B} \vec{B}...
19. ## Thread: distance between dielectrics

by julian403
Replies
0
Views
836

### distance between dielectrics

I have the next problem:

212

What I did is: First I calculated the carge in the in the inner sphere

\dst q= 20[\frac{Kv}{ m}] 4 \pi 6 {\varepsilon}_{0} {(0.01[m])}^{2}=1.33 [nC]

by julian403
Replies
3
Views
900

### thanks, but I'm still confused. Why Radiation...

thanks, but I'm still confused. Why Radiation pressure is a necessary consequence of momentum conservation? Because when a body increase the temperature, the momentum is conserved too. Adding all...

by julian403
Replies
3
Views
900

There are two phenomena when an Electromagnetic wave on a body inside, one is an increase of temperature and the other is radiation pressure.

\dst T= \sqrt {\frac{I}{\sigma}} and Pr =...
22. ## Thread: Electric displacement density

by julian403
Replies
0
Views
795

### Electric displacement density

I always had a doubt about electric displacement density \vec{D} which it's electric displacement/surface.

D=\frac{\psi}{S}

first of all
\psi is electric displacement and, this is an other...
23. ## Thread: Electric generator

by julian403
Replies
4
Views
1,589

### thanks, but the direction of magnet fields are...

thanks, but the direction of magnet fields are diferent in coils 1 and 3 than 2 and 4 and the variation of flow wil be opposite so potential will be opposite in these coils. That's my doubt. Or...
24. ## Thread: Electric generator

by julian403
Replies
4
Views
1,589

### Electric generator

I'm wanting to do an electric generator. Seerching I found the design easier. Magnets must necessarily be in the rotor to not use brushes or coals.

172

tTe principle of generator is

\dst...
25. ## Thread: virtual displacement

by julian403
Replies
7
Views
1,342

### thanks for the answer, let me see if i got it. A...

thanks for the answer, let me see if i got it. A system can make a lot of path, at least are the potential paths. When i find with the langranian the path which minimizes the energy, this is the real...
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