Core Definition and 484 Threads

Hi, Does anyone know if anyone else has made a mock demonstration of the dynamo effect of the Earth's core? I've heard that the core is supposed to be made of a liquid metal sphere with a solid metal core. When they spin, they make the Earth's magnetic field. The question is, if the...

if a tunnel is bored through the centre of the Earth and a pebble is dropped into it then the pebble will do what ?...A)stop at centre...b)perform s.h.m.

why density of core of the sun is changing ? please give me brief explain with calculation

Hello all, I am trying to determine if my machine is 64 bit or 32 bit, according to this site: http://support.apple.com/kb/ht3696" the Intel Core 2 Duo I am using is 64 bit, but when I run the following code #include <stdio.h> int main(int argc, char **argv) { char c; int...

I was reading an article over the weekend that the Moon has evidence of a "final" volcano on it's "far side." I am working on something that suggests the Moon would be too small to have had volcanoes, and this didn't fit with my assumption. I then reasoned that based on size, and based on the...

How can random electron currents in the Earth's core create a ordered magnetic field? What makes a current in the Earth be north or south what is the difference between a north current and a south one? How come if the magnetic field is strongest at the centre of the planet how come where it...

Homework Statement Consider a simple model for the interior of the Earth: there is a spherical iron core with constant mass density ρ0 and radius a; outside the core is "rock" with constant density ρ1. Use these values for the densities: ρ0= 8.90×103 kg/m3 and ρ1= 3.80×103 kg/m3. The radius...

I cannot seem to figure this out. I know total core losses at 120Hz and 60Hz are 100w and 32w respectively for some unknown constant ac voltage. I can't seem to figure out how to go about finding core losses at other frequencies or separating eddy and hysteresis losses. Can anybody shed some...

What is the difference between them? Which of them is used in building websites and which of them is used in designing application for mobile phones and other systems?

If a small black hole were to fall into a star or brown dwarf, presumably it would initiate accretion and fusion in a shell around it. Can such an object be stable over any decent timescale, or would it undergo variability/significant mass loss/supernova?

We all know that Earth's core is relatively hotter than the Earth's surface. And with this temperature gradient, there must me a loss of heat from the Earth's core to the surface and then to atmosphere and outer space by convection and radiation. So, how much time it would require for the...

So I was looking some stuff up on Quasars on Wikipedia and noticed this picture. http://upload.wikimedia.org/wikipedia/commons/a/ab/2003-03-b-web.jpg It says that this is a Quasar Core. What exactly is the difference between the left and right pictures here? Did they block out the light...

I have completed Quantum Core courses as well as GR and it seems there is something I am missing before taking QFT/QED courses. Is there another subject between?

I'd like to start a new thread regarding the technical and numerical aspects of the radiation releases of Fukushima Daiichi. Does anyone know how big the iodine and cesium core- and SFP inventories were before the accident happened? I'd like to compare the released amount to the amount...

Hello everydody. Well i need to write a repor (5 pages maximum) about Core Collapse of Massive Stars to my discipline Stellar Structure and Evolution . The problem is that i have read some books like https://www.amazon.com/dp/0387580131/?tag=pfamazon01-20 and i have no ideias. I gained...

Homework Statement Estimate the gravitational potential energy released in the collapse of a 1.2 solar-mass core from an initial density of 10^9 g/cm^3 to a final 10^15 g/cm^3. Homework Equations The Attempt at a Solution The book doesn't provide much guidance on this. I was thinking of...

Dear all, Hi I am involved in a project and I want to model an induction machine with two three phase stators. The frequency and number of poles of the two set are different. How can I write a formula for the core loss of the stator? There are two sinusoidal waveforms at stator. Can I use...

As part of an experiment, I'm looking to irradiate PtCl2 in a reactor core, PtCl2 will be contained in an Al container. What's the worst that could happen?

Hi everyone, I'm new to this forum. I'm planning to build an alternator/generator but I can't seem to information regarding the benefits of the height/length of the teeth in the stator core as indicated by the arrow in the picture below [1]. I know the width of the teeth determine flux...

Is there a difference in inductance of an inductance with magnetic material whether it is magnetized or not. Meaning is there an increase of inductance if the core has been magnetized ( become magnet) vs the same material but not magnetized? Does magnetization increase the \mu of the material?

Say, I want to design, 220 / 12 V 100VA transformer. We have V = 4.4BfNA (V is applied voltage RMS, B is peak flux Density, N is no. of turns, f is frequency, A is core cross section) so, B = V / (4.4 f NA) If i use iron core, there is limit to the maximum value of B without excessive...

Like the list of invited talks at the biannual QG conference, the list of lecture series at the ESF-QG schools gives a snapshot of where the field currently is. What work stands out---who is giving the main talks---what topics get mentioned in the abstracts. So it's something to learn from...

Researchers have found seismic evidence for a 300 km thick layer in the outer core formed of light elements expelled upon inner core solidification. They believe the gravitational energy released by this compositional convection is a key input to the energy that drives the geodynamo...

I understand that the massive object at the center of the galaxy is visible in both radio waves and X-rays, although not in visible light. I also understand that an image has recently been taken of this object in the infrared wavelengths. Have there been any attempts to do spectroscopy on...

My laptop has a duel core Intel Centrino processor. Whenever I write programs in C/C++ in Visual Studio and run programs which should execute at full speed only one core seems to be doing anything. Some programs seem to be able to make full use of both cores, is this possible in Visual Studio?

This entry on the voice "SUN" in wikipedia is correct? How can this can be possible? And if this entry is true how can be possible to create a small fusion reactor on the Earth? the entry is: The energy production per unit time (power) produced by fusion in the core varies with distance from...

I am thinking to use the air core to make transformer to get better linearity behaviour, but I found air core often use in high frequency,so can I use air core for 50Hz? what is the difference between high frequency and low frequency? Thank you!

Hello Everyone, I'm interested in designing my own custom electric motor for some experiments and I am trying to do some research on some of the various laminated steel materials available. I have a decent working knowledge of general magnetic material properties, saturation characteristics...

Hypothetically: If a hollow sphere with a human inside were placed exactly at the centre of the Earth's core; then how would gravity affect the human (or any mass for that matter).

Quite sure I didn't Google properly, but I'm not well versed so is to be expected. Did find this forum, and have a few times previous to be helpful. Now what I'm wondering is what would happen if mass from the center/near center of the Earth where moved and dispersed, how would this effect...

When designing a core lattice, which one of the thermal-hydraulics and neutronics consideration are important?

Hello, Those days I wonder if the magnetic field from the Sun, could make the Eddy's currents inside the core (ferromagnetic) of our planet, because of the rotation of the Earth. (like a induction cooker) It would result a magnetic field on the Heart, and if the magnetic field from the Sun...

As previously described,* might one drop a 10x10x10 ft cement cube at 15-20 ft from Gulf of Mexico oil/gas conduit. The intent is to seal up such conduit extending down ~1000 ft below sediment surface. The non-compressible fluid collapsing and sealing soft metal casing and compressible gaseous...

Core Drop As previously described, might one drop a 10x10x10 ft cement cube at 15-20 ft from Gulf of Mexico oil/gas conduit. The intent is to seal up such conduit extending down ~1000 ft below sediment surface. The non-compressible fluid collapsing and sealing soft metal casing and...

I know this sounds silly but hear me out. I'm a second year uni student intending to major in physics and I was going fine with physics until the start of the year when I encountered Atomic, Nuclear and Condensed Matter Physics(ANCMP). I tackled it again and again dedicating long periods of time...

this is the formula for calculating core loss http://power.thayer.dartmouth.edu/pictures/function.jpg alpha, beta and k are constants that have to do with the material of the core. what are f and B, and what exactly does Pcore mean

can i solve for core loss of a cylindrical inductor by knowing the dimensions of it and the material it is made of?

I have a few questions regarding codes typically used in core design: 1) Which codes need to be coupled with a TH module and which do not? From what I have gathered, steady state codes can be coupled with a code like RELAP to model transients. 2) Are independent codes that are coupled to...

Homework Statement Sorry if this is the wrong section. Please redirect me if there is a more appropriate one. I'm looking at the timing spread in the time of flight of photons through fibers in a fiber optic faceplate. Essentially the minimum time for photons to propagate through one of the...

Homework Statement We suppose the nucleon density of a spherical nucleus where r<R1 is constant, and where R1<r<R2 the density linearly decreases to 0 at R2. We call the surface nucleons (Number Ns) the number of nucleons contained in the volume R1<r<R2 and core nucleons (Nc) the number...

I am just an electrician doing experimental work with a Stubblefield coil. From what I've read the most common steel is 1018. If Stubblefield used a common bolt I assume this would fall into the 1018 realm. Would the 1018 iron core be better cold rolled or hot rolled for the magnetic collapse as...

I got a few questions about transformers.. I understand there is a primary winding and secondary winding wraped around a iron core. Now for the primary connection - take 7.2kv 1 phase line and connect it to one side of the winding and take ground (earth) to the other winding end. On the...

One of my teachers keeps on saying that her subject is one of the most difficult, without any proof, and she says this everyday, and it's getting old, so I thought I'd like to take an informal poll to determine the truth: What is the most difficult core class for physics graduate students out...

Would a single 10GHz CPU be as fast as a quad-core CPU with each core running at 2.5 GHz? I would imagine that the caches on the Four processor cores would give it a performance advantage over the 10GHz single core. The way CPU manufacturers went after the days of highly-clocked processors...

Homework Statement SO i don't have the radius or the volume but i have an estimate of the density 14.5 10³kg m-3 Im really uncertain of the formula needed to A. get the radius without the volume and vice versa. PLEASE HELP! Thanks in advance! Homework Equations The Attempt at a...

Homework Statement A current transformer has a primary winding of two turns and a secondary winding of 100 turns. The secondary winding is connected to a ammeter with a resistance of 0.25 ohms. the resistance of the secondary of the current transformer is 0.75 ohms. The value of current in...

Homework Statement A hole is drilled through the center of a ball of radius r, leaving a solid with a hollow cylindrical core of height h. Show that the volume of this solid is independent of the radius of the ball. Homework Equations V = \int_{a}^{b} 2\pi x (f(x) - g(x))...

I've been attempting to spec a toroidal inductor--what core size, what material and how many turns? I happen to be looking at some made of the material Kool Mu. The material if ferrite, so I presume most of the core loss is hysteretic BH loss, as ferrite doesn't conduct well. Anyway, all...

Back in the 1970's and 1980's I was told that the NRC wouldn't license a design over 3800 or 4000 MWth. The new designs must be considerably higher (another post mentions the Hitachi at 1700 MWe, seems like that must be approaching 5000 MWth core power). Was I given bad info way back when, or...

Homework Statement After determining the average density of Mercury as 5.43 x 10^3(kg/m3), you may calculate the size of Mercury's core. Assume Mercury consists of a core and a mantle+crust, with core composition being similar to Earth (7,800(kg/m3)). From space missions and studying...