Core Definition and 484 Threads

What is the difference between a rocky planet's core and the core of the sun?

Hi Quick question related to magnetism If I have a magnetic core and place that core onto a magnet, then roll the core on a flat surface ( whilst its still on the magnet), does that increase the permeability and magnetic field of that core ? If so, what is the theory behind that. thank you in...

There is a short movable section of cylinder shape in a O-ring magnetic core with DC coil, of course, there are 2 air gaps between the movable section and stator main section. My question: if rotate the movable section, is there a bunch of twisted magnetic lines? The rotation does not change the...

This is not for any kind of homework ---the last time that I went to school was 30+ years ago. However, I am a curious person, I've been asked by other people who know that I love science and I need to calculate this: As you will most possibly know, a misreading of this paper by the media...

I found a box of air core solenoids and was hoping someone could me think of a useful lab to use them for. They are about 700 turns each. They carry 7 to 10 amps. However I think I think I would only be able to provide 3 amps because of the power supplies I have. I would like to use them to do...

I just started my master's degree and I'm currently taking a course in astrophysics. However, it seems like I have misunderstood what prevents stars from collapsing (I will elaborate below). Why is it, that as soon as a massive star has finished the fusion processes, the collapse will happen in...

All the inductor components I’ve see are made with a circular core instead of a cylindrical core. Are there any advantages to this design in terms of field strength relative to input current (assuming the same number of turns of wire)? In the field strength equation, is “coil length” always...

Hello everyone, I would like to know if anyone could help me with my apdl model. I have created a model of a honeycomb sandwich panel but the solution is not converging, is there something that I should pay attention to? I have connected the core and the plates simply with NUMMRG command...

Christoph Schiller, "From maximum force to physics in 9 lines -- and implications for quantum gravity" arXiv:2208.01038 (July 31, 2022). This paper asserts that nine propositions can be used to derive the Standard Model and GR and can point the way to quantum gravity, although he cheats a bit...

I don't know if this is really stupid, but why isn't Earth's core a gas considering that its hotter than the temperature at which each of the metals turn into a gas?

I am trying more generally to find the equation of the fore exerted by an electromagnet. The one that I keep finding is F=((NI)^2 A mu0)/2X^2. N is turn number, I is current, Mu0 is permeability of free space, A is the area of the core and X is the distance from the electromagnet. I take...

My understanding of why Mars lost its atmosphere was because it cooled down too much internally and that when this happened, the planet lost its magnetic field that helped protect it from solar winds (which then ended up stripping away the planets atmosphere). Is there anything that people could...

So there is a post going around the facebook groups about what would happen if we could pour a Sun sized bucket of water onto the sun, the claim being that the sun would gain mass and become a bigger, hotter burning blue star. I know this cannot happen but I was just curious as to what would...

Hello all, I'm playing around with a PIC + LCC Tank to send - at a 5MHz frecuency - some numeric data via BPSK. The receiver is a loop antenna placed in the ground. The sender antena (L) is a ferrite core solenoid (N=10). As having a larger core, or increasing the Number of coils around the...

The question is simple. The molten stuff inside the Earth will get a smaller volume when it solidifies. Will the Earth increase its rotation speed in reaction to this? What about the magnetic field?

I'm doing a simple RL Circuit Lab where students use 800- and 1600-turn air core coils to measure the time constant. Experimental results very nicely agree with predicted results. However, when students insert a steel (or iron) core in the coils, experimental results are far different than...

Hi, I have a toroid of a soft magnetic material (any). I wind the complete toroid with single turn coils and connect all their terminals in parallel. Then I wind a second layer of single turn coils on the previous layer and so on. I want to calculate the equivalent inductance L. I calculate it...

I would like to know how the negative xenon load varies with core burnup. Does it increase or decrease as the core progresses from beginning of life to end of life? What is the reason for this change? Any help will be much appreciated

What happens to the material not involved in the core collapse of a supernova? This would be the outer portion of a star or any cloud that surrounds the star. All material to infinity or does some material remain close -- gravitationally close that might collapse if it could. thanks

This is one of those 'oh, I am not sure I know the answer' kind of thoughts. The strength of magnetic flux in a transformer core is a function of volts per turn, Faraday figured that one out. So, if I have a light load on a secondary (let's say it is pure ohmic for now, let's not confuse it)...

I am doing core loss calculations in Ansys Maxwell for a project, in which I need to draw a helical coil around a rectangular core to get a more realistic model. But I haven't really found any helpful material. I don't know if its possible, but if it is I would really appreciate your help. Thank...

Interesting article. At first I thought the article was saying that for many parents, helping their kids with their math homework was the hardest because maybe they weren't all that great at math themselves. But the real reason is that the "Common Core" math methods used in primary school...

I can easily calculate the core and currents required for the coil and core, i get confused do the the external field, any help please.

In previous manifestations explaining the Coronal Heating Problem, scientists pointed out the discontinuity between a very hot Solar interior, the 'cool' Photosphere and a Hot Corona. According to the newly modified entry in Wikipedia, they now explain the discontinuity only between a cool...

Some Variable Frequency Drive manufacturers (such as Allen Bradley) supply a toroidal Ferrite core to wrap the outgoing cables around to reduce EMF. My question is, if a company doesn't supply a ferrite core, how do I work out if one is needed, and how do I correctly size it? I understand that...

I've attached a figure I've made; I know I'm to assume the Earth is a perfect sphere in this case. Assuming the 103 degrees is measured as latitude, I've calculated the distance in kilometers (Xp in the second equation above) to be 1.1453e4 km. I know I need u = p at the turning point, but not...

a) In the rough approximation that the density of the Earth is uniform throughout its interior, the gravitational field strength (force per unit mass) inside the Earth at a distance r from the center is gr/R, where R is the radius of the Earth. (In actual fact, the outer layers of rock have...

It is solid

In a recent Scientific American article, Tammy Ma claims Jupiters core is solid diamond. She claims her work with lasers has demonstrated this. Any thoughts?

Whats the minimum kinetic energy a neutron must have in order to trigger the fission of for example a lithium core ?

Mars apparently does not have a molten core, therefore no magnetic field. If Mars had a substantial moon, say Ceres, would the tidal action melt the core in Mars? And, perhaps, allow Mars to retain an atmosphere.

I have a question regarding Neutron Star cores that perhaps PF could clarify for me. Given a millisecond spinning NS, and given that its gravity decreases toward the center, being a spherical body, does centrifugal force displace the core material outwards to form an empty obloid-shaped cavity...

Hello everyone, i am Ali a PhD scholar i need some help regarding MCNP, i wand to model a pwr core with spacer grid but i don't know how to model spacer grid can anyone help? Regards

Hi, I am going to wind an tapped toroid inductor for a LCR circuit in an equalizer. I have calculated the number of turns I need for each winding. This is my first time winding an inductor so I need to get some things straight. What to do with the 10 kHz tap, should I twist a wire with the 12...

If a (maxwells) demon were to snatch the core from the sun, what would the result be? would the remaining outer layers coalesce into a red dwarf and just continue on without much fuss? Would the core, removed from the sun, undramatically just expand out to become a red dwarf also? Just a silly...

Would neutron star cores be a good system to study quantum gravity? Core densities are higher than nuclear material. Is it possible cores exhibit QG effects?

I found a few research papers with regards to a special type of microsized/nano particles mixed within an oil creating a special sort of ferrofluid or liquid which among other things has the property of extremely (gigantic) high dielectric constant. Now such a fluid would be ideal for a variable...

If the abundance of Uranium in the Earth is around 10ppb... then the total mass of U in Earth is around 3e19g that's around 1e19 moles (virtually all U-238), corresponding to 3e23 decays / second, which would generate at most 2-3TW of power (attributing the entire 52MeV decay chain energy to...

For finding magnetic field ##B##, We see this question like two Solenoids. for the first one, we have ##\int B ds = \mu I## so ##B x_0 = \mu I n x_0 ## so ##B = \mu n I##. For the second one we have ##B = \mu_0 n I##. For the Inductance we have ##L = \mu l n^2 A## so we have ##L_1 = \mu x_0...

Summary: hypothetical experiment, how would neutron core behave in such a circumstance such as, if we teleport 1mm^3 of neutron star core from it outside. how would the 1mm^3 neutrons behave? 1. Would it be stable/no change 2. Would it decay into cosmic radiation 3. would it decay into...

I read the limits of typical ferrite cores and it seems that most sources claim that they tend to work somewhere up to 1 Mhz. Surely they work great under that frequency, but is there any material that could provide a core material for a wide frequency range starting from few tens of Khz up to...

Here, i have provided the description of the mean molecular weight from my course notes as well as my workings. I'm not sure about my values for X and Y. It states that X=1 if all of the hydrogen is ionised which i think the 1 represents 100% hydrogen but the core is also made up...

Hello friends. I know there a lot of complex mathematic involved in this subject and I'm not currently very knowledgeable in that area but, in simple terms, what would be the simplest way (theoretical or practical) to determine the magnetic saturation of a cylindrical soft iron magnetic core...

Hello! I want your help for core losses on how to calculate core loss on a toroid core?

I have 150 x 100 x 60 M4 grade toroid core and same grade slit coil, I need to 180 x 100 x 60 in my design purpose.i would like to add OD 20 mm. my suspicion is a slit that can be added should be on the same grade?

I am currently setting up a simulation for thermal hydraulic analysis of an AGR fuel bundle. However, the walls in this type of reactor, have a specific roughness that promototes turbulence which in turn provides better heat transfer characteristics. I am struggling to find data online to...

How does changing the core of the solenoid affect the current induced in the loop?

I know the basic equations of a solenoid carrying a current, the consequences of having an iron core inside one, and how that derives from Ampere's law. But these suggest that the only figure of merit is the cross section area of an iron core and the solenoid, not their shape. Thinking in more...

Hi, I want to make a simple nuclear reactor core simulation to calculate the thermal power production. Is there any open source code with interface (or not) that you recommend to use? The core have cylindrical shape with Uranium( up to 90% enriched) molybdenum fuel,Beryllium reflector and one...

Hello friends of the forum! I'm here with a doubt! I have a solenoid of cross-sectional area 5cm and length 9cm with iron core of relative permeability (ur) 9,000, I wonder how to calculate this silenoid!