as you may or may not know, we are swimming in cancerous radiation on a daily basis here on the surface of Earth. I’m noticing kids being inundated with wireless gadgets at younger and younger ages. I am guilty as well! We let our 4 year old have iPad time as long as he is surrounded by orgonite. But I think it’s wise to not have them around any wireless technology if we can help it. Society cloaks all this technology as “innovative and cutting edge”. “Go get the new #iphone6! Get one for the whole family!” Their skulls are not thick enough to fend off that radiation and if we continue at this “wireless” pace, more kids will have brain cancer by the time they’re teenagers. This is by design folks! #EMF #cancer #cellphones #radiation #ipad #iphone #icancer
hey! i'm doing electric power at school and i'm really confused about which equation to use when you're finding the induced emf? (-n∆flux) / (∆t) or nBA2pif???? thank you!
Hi! Both equations you mention are actually very valid to help you find the induced EMF! Since I am in the midst of making posts about electromagnetism, I’ll go through this is detail.
Although I will use both calculus with vectors and scalar, pre-calc representations, for your level I’d recommend the equations with non-infinitesimal changes (signified by an ‘approximately equal to’ ‘≈’ symbol and a ‘Δ’ symbol in place of ‘d’.)
The first equation
If we consider the first equation for induced EMF you’ve provided, which states that
(equation 1) where N is the total number of turns in a loop of wire, t is time and ΦB is the flux of an inductive magnetic field B through a surface S (which we can define for each situation,) given by
in which: “⋅” represents the scalar (‘dot’) product; ϕ is the angle between the field lines of the magnetic field and the normal to the surface. It is worth noting that the cos ϕ part of the expression comes directly from the scalar representation of the dot product.
This is the most general expression for the induced EMF – describing the effect a changing magnetic field (or a moving/changing surface, for that matter) has on the motion of charges through a circuit. It tells us that when we move a conducting rod through a loop of current-carrying wire, we expect to observe a current induced through the rod since lines of flux are being intersected by our rod (which is our surface, in this case.)
However, if we move our rod through the wire loop—which will, for now, be carrying a DC (i.e. direct current; non-changing) signal—and hold it at the centre, we notice this new current produced by the induced EMF will drop off in proportion with how fast we move it through the field. This is because less lines of flux are being intersected per unit time, signified by the ratio of flux change to time change. This is an important feature of electromagnetic induction because it means that if the current in the first wire is constantly changing, we need not vary the position or dimensions of our rod to allow an induced current.
The second equation
A changing field is produced using an AC circuit, which varies the voltage from a positive value to a negative value within a specific time frame, given by the frequency f of the signal which oscillates over 2π radians, allowing us to define the angular frequency ω = 2πf. This principle is vital to modern life and has applications in communications methods such as Wifi, radar, GPS and Blutooth. I hope to write a set of posts about radio communications in the future but we’ll have to wait and see whether I end up having time!
We can visualise the inductive effects of an alternating current by considering how it is principally generated – using a rotating magnet in a solenoid of N turns (a solenoid is long of wire coiled multiple times to form a sort of wire tube.)
Let’s define our flux surface as the area of a wire loop so we can see the how the flux of the magnetic field through the solenoid. To simplify the situation, we’ll ignore the integration and say that S := A, where A is the cross-sectional area of the solenoid, which means that
It is worth noting the time-dependency of the angle here: our magnetic field source is now rotating, so the angle between the field lines and the surface normal will be changing with time, too! Thus, with a little bit of thinking, we can determine ϕ(t).
We know our magnet, which is producing field lines through its poles, is rotating with an angular frequency ω = 2πf and we know that f = 1∕T, where T is the time period, so
This may help us conceptually when considering the timing of the magnet’s angle, since we can express the time in terms of the total period of the motion.
Let’s say at time t = 0, the magnet has its North pole towards the surface; the angle here is zero, meaning the induced EMF is at a maximum.
One complete revolution later, where t = T, the magnet has returned to its original position and now has ϕ(T) = 2π = 0. Therefore, by substituting the current time for our period we find that
Through rearrangement (multiply both sides by t,) this becomes
and, since we know that ϕ(T) = 2π
and we know that ϕ(T) = ϕ(t), so finally:
This is our time-dependent angle, discovered through inference alone! We can check this for any stage rotation in terms of the period and will find the correct angle. This expression throughout in oscillations throughtout physics.
Now we have to use a little calculus. Recall our original expression for the induced EMF, given by equation 1, and substitute our new expression for the magnetic flux density:
which, when evaluated at t = 0 (or t = T, and so on) for maximum EMF, yields the equation you provided:
From following the derivation through, it can be seen that this expression outlines the maximum EMF induced in a wire which follows a regular looping pattern around a cross sectional area A (as with a solenoid of N turns) by a magnetic field density B for some alternating current (or regular oscillation) having a frequency f. This could be used for any AC-based induction, any system involving periodically rotating magnets or something involving periodic changes in solenoid dimensions. The key point here of that this equation requires periodic oscillation oscillation and, evidently, this describes a much more specific scenario than the first equation.
The mathematical derivation itself may be a little difficult to follow as it uses mathematics that you haven’t explicitly met yet but the key concepts lie in the derivation. Just try to understand the scenario outlined and the arguments made so you can know whether a scenario is applicable.
For a little more information, which should be more aimed at the specific syllabus you are studying, see the following posts:
Orgone energy is becoming stronger every day. When once we would see chemtrails in random photos, where the photographer doesn’t understand the sky he is photographing, we now see orgone transmutations. The toxins are being gathered up in spiraling vortexes and removed from the sky, and water vapor is being liberated. Birds love orgone energy and a frequently seen circling in these vortexes. I have seen more and more blue skies, natural clouds, and transmuting skies in media worldwide. The photographers have no idea what they are capturing, but the fact that we now see these skies all over the world, where 2-3 years ago we saw chemtrail skies in ads and media, shows the major shift we are seeing in humanity taking back its power.
//My study mind map on Emf and internal resistance for AS Physics. The exam is on a few days away and with a busy work schedule this weekend I’m spending every second I can studying for these exams! I hope you all are feeling confident about any up coming examinations!//
so most of you know that i suffer from a chronic pain disorder but here’s a possibly crazy theory that i have devised. please keep an open mind.
first off, i suffer from fibromyalgia; a chronic pain disorder that affects most joints (ie wrists, elbows, knees) and contains a whole multitude of symptoms including headaches, fatigue, weakness, insomnia etc.
the most annoying thing about the disorder is that doctors have no clue what causes it, so therefore there is no direct treatment or cure. (fun!!)
so here’s where my theory comes in.
i first started experiencing fibromyalgia symptoms (beginning in my knees) in september 2014.
interestingly, this is only a few weeks after i first used a ouija board with one of my friends.
my theory is that perhaps the same spirit that i disturbed with the ouija board has attached itself to my energy and is draining me and making me feel this way?
here are some things that make me think this theory isn’t so crazy:
many fibro patients indicate that they have an intense sensitivity to emfs (electromagnetic fields) that are emitted from devices like mobile phones and tvs. and what is the most popular device used for finding a spirit? an emf reader. i kinda want to buy a cheap one to see if i have a high reading (i probably will as i can feel myself constantly buzzing all the time)
it has been documented several times that in extreme situations, fibro patients with high emf levels can interfere with electrical devices ie turn off stereos, turn off street lights and even stop computers from turning on. (a link to a story here) i have experienced this myself once when my ipod would scroll up/down for no reason and kept turning on when i wasn’t touching it.
it seems that fibromyalgia is a hugely popular disease among psychic mediums (link)
also my hands and feet are beyond freezing all the time no matter if i’m using them or not??
anyway its safe to say im going to be wearing crystals/a cross everyday and looking at spirit deattachment
i would love to hear some feedback on these ideas so pls message me if you have thoughts!
Here’s some news about cell phones and cancer which even the mainstream media has found impossible to ignore. The International Agency for Research on Cancer (IARC), an arm of the World Health Organization (WHO), has declared after a review of the research that cell phones are possible cancer-causing agents. The expert panel ruled that there was some evidence that cell phone use was linked to two types of tumors—brain tumors (gliomas) and acoustic neuromas