Induction Definition and 999 Threads

Hi all, I have a question which relates to induction and one potentially useful property of superconductors which seems to suggest one intriguing posibility. I won't say what just yet since my science is potentially a bit rusty, so don't want to sound like a fool. As I understand it, after...

Prove by mathematical induction: (2n)! < (2^(2n))*(n!)^2 , for all n=2,3,4... I know that to start you must prove that it is true for n=2, (2*2)! = 24 < 64 = (2^4)(2!)^2 Then you assume that n=k and show tha n=k implies that n=(k+1) (2k)! < (2^(2k))*(k!)^2 ... At this point I...

Homework Statement A long, straight wire is surrounded by a hollow metallic cylinder whose axis coincides with that of the wire. The solid wire has a charge per unit length of + λ, and the hollow cylinder has a net charge per unit length of +2λ. From this information, use Gauss's law to find...

Hello All, I have an arcane curiosity that cannot be answered anywhere I look (including Griffiths' intro electrodynamics book and the internet). This question seems so simple but I may just be over-thinking it. If there are two square, parallel, finite, conducting plates and a point...

Consider 2 cases case 1: no of rotor poles = 2 no of stator poles =4 case 2: no of rotor poles = 4 no of stator poles =2 What will happen in case 1 & 2 ? Will Induction motor run?

In a 3 phase slip ring Induction motor, 3 phase balanced supply is given to rotor winding & stator winding is short circuited . Then rotor would - run against the direction of rotating field. Can anyone explain this phenomenon?

Homework Statement A metal rod (1/sqrt(pi)) m long rotates about one of its ends in a plane perpendicular to magnetic induction of 5*10^-3 T. Calculate the number of revolutions made by the rod if EMF induced between the ends of the rod is 1.5 mV. I have been thinking about this problem for...

if i increase the amperage in an induction motor, will the induction motor spin faster? and vise versa?

EDIT! Hmmm, sorry. What is the difference between the origin of the emf in a small current loop when; a) a magnet is stationary & the coil moves, b) the coil is stationary & the magnet moves This was the original message, now realized to be incorrect. A current is generated when a...

Hi all, I've been struggling with a large piece of coursework. been quite stressed latley and now I am struggling while aproaching my deadline. i need help answering this question. Use mathematical induction to show that S(n) = 3 × 2 n-1 -2 is the solution for the recurrence relation: T(n)...

How do I prove a formula/rule or something by mathematical induction? Please give me a few examples or resources and explain it as best you can because I think I'm messing up some how.

Is it a solid proof to show that the closure of a union equals the union of the closures of the sets via induction?

Hello The equation for power consumption of a three phase induction motor is given by the equation: P = sqrt(3)*V*I*(PF) Does this differ from the power that is delivered to the motor. For example, if a motor is running at 460 volts, 30 amps with a PF of 0.82, then the power...

Well, passive RFID tags has to be inducted to work. When the induction reaches the tag, it powers itself and then the microcontroler sends a RF signal to the reader, with the product ID, rigth? What I want to know is: what type of induction does it use? How the induction radio frequency...

I am idly curious about induction heating; specifically for heating 80L-100L of water from 20C to 100C as efficiently as possible with an emphasis on as little waste heat going to the surrounding environment as possible. I have done some precursory reading (...

Prove that: 1 + 1/√2 +...+ 1/√n < 2√n Work: So I've done the base case of n = 1, and I've set up the Indutive hypothesis as assuming n=k as 1 + 1/√2 +...+ 1/√k < 2√k and for the inductive step: 1 + 1/√2 +...+ 1/√k + 1/√(k+1) < 2√k + 1/√(k+1) now I'm having trouble trying...

Homework Statement https://sphotos-b.xx.fbcdn.net/hphotos-prn1/69668_10151632316928154_624610826_n.jpg x^n-y^n = (x-y)*(x^(n-1)+x^(n-2)*y+...+x*y^(n-2)+y^(n-1)) from Number Theory by George E. Andrews Homework Equations The Attempt at a Solution (x^n-y^n)/(x-y) = the sum for the first n...

Hi, I want to heat the FEL beamline for the outgassing process with an induction heater. What frequency should I use in the driver circuit of the heater? The geometry of the beam line as you can imagine is cylindrical. And do you have any experience about it? If its so, I will be...

I do not understand why ferromagnetic materials are more easily heated by an induction oven than a non/low ferromagnetic material such as copper or aluminum. Are Eddy currents more easily induced into a ferromagnetic material than a conductor lacking a high ferromagnetic property? Why is it so?

Homework Statement Let a1=2, a2=0, a3=-14 and an+1=9an-23an-1+15an-2 for n>= 3. Show by induction that an=3n-1-5n-1+2 for n>=1.Homework Equations The Attempt at a Solution Ok this is annoying to type... Base Case is true, which is the easy part. The induction part I am not going to list all...

I am looking for something that should be relatively simple to find, but as such, I have not been successful. I know that an electric current can be created by moving through a magnetic field. I have found equations that indicate this can be based on the velocity and the length of said object...

Hi all, I have a conceptual difficulty with the idea of induction of a current in a wire due to a changing magnetic field. Initially I was very comfortable with the idea. Upon seeing the typical setup of a square wire being rotated in a region of uniform magnetic field, I was happy to accept...

I am having trouble thinking about self induction in the primary coil... My text says in standard situation the self induction voltage is same as the primary voltage... My question is how does current flow in the primary coil then? Please tell me where I am getting this wrong?

This is a question I've been trying to figure out. I'll try my best to formulate it, so apologies if it's a bit ill defined! Suppose you construct a finite parallel plate waveguide of PEC(perfect electrical conductors) and PMC(perfect magnetic conductors) so that the top/bottom plates are PEC...

Hello, when a coil rotates in a magnetic field an AC is produced at the ends of the coil but do that electrons come from the coil wire ? If yes, shouldn't the coil run out of electrons after some time ? thank you

Consider a magnet moving towards a coil. We know that the motion of the magnet will induce a current in the coil and the direction of this induced current is to oppose the motion of the magnet. Now does the magnet experience resistance to its motion immediately as soon as it starts...

On another site, a user asked for help showing: $\displaystyle \sum_{k=0}^{2499} \frac{1}{\sqrt{4k+1}+\sqrt{4k+3}}>24$ The first respondent asked if the OP was familiar with mathematical induction. The reply was that induction was the topic of the next chapter in her course. Another suggested...

Relative motion between a permanent magnet and a conductor wire produces electric current in the wire. Would induced electric current be greater in a wire made of "magnetic" material like iron, "non-magnetic" material like copper, or it doesn't matter? In other words, is there relation between...

The principle of induction states that: Suppose\ that\ P(n)\ is\ a\ statement\ involving\ a\ general\ positive\ integer\ n.\ Then\ P(n)\ is\ true\ for\ all\ positive\ integers\ 1,2,3,...\ if\ (i)\ P(1)\ is\ true,\ and (ii)\ P(k) \rightarrow P(k+1)\ for\ all\ positive\ integers\ k. I found...

Homework Statement Prove that 2^n > n^3 for every integer n >= 10 Homework Equations a) Prove for 10, b) assume for k c) inductive step for k+1 The Attempt at a Solution a) 2^10 = 1024 10^3 = 1000 1024>1000 b)Assume 2^k > k^3 c) 2^(k+1) > (k+1)^3 (2)(2^k) > (k+1)^3 (2^k) > ((k+1)^3)/2...

Homework Statement Suppose that if there are at least 2 people in a room and each person in the room shakes hands with everyone else, but not with himself. Show that the number of handshakes is (n^2-n)/2. Make sure to show P(1), P(k) and prove P(k+1) Homework Equations The...

Hello folks, I have an induction problem that I have been working on, and I am at my wit's end. If anybody could provide me with a nudge in the correct direction, I would greatly appreciate it. I have attempted to factor out a number of terms to find something remotely intuitive here to present...

I have a 13 layer 130mH induction coil that failed and now registers 6.64mH. During the failure analysis the coil was unwound layer by layer and the induction dropped in steps of 0.7-1.5mH to a value of 1.3mH until the 8th layer was removed the the inductance increased to 5.4mH. Then the 9th...

Homework Statement \sum i=1 to n\sqrt{1+(1/i^2)+(1/(1+i)^2)} = n(n+2)/n+1 2. The attempt at a solution First I did the base case of p(1) showing 3/2 on the LHS equals the 3/2 on the RHS. Then I assumed p(k) and wrote out the formula with k in it. Then prove p(k+1)= p(k)+...

Homework Statement Here is this problem: I have the solution http://www.proofwiki.org/wiki/Leibniz%27s_Rule/One_Variable This is where I get stuck.. Where it says: 'For the first summation, we separate the case k=n and then shift the indices up by 1.' Why does this lead to the...

We know that 1)a change in current and voltage in a coil may result in induction in other stationary coil..this induction is directly related to frequency..ie The higher the frequency the more intense the induction effect. 2)we also know that there is no induction in case of DC current flow...

Hello, I'm trying to find out how much energy an induction motor pulls over a 24 hour period when connected to a resistive load. The only data I have are the specifcations of the motor, so I can estimate how much energy it will draw based on what capacity it might be running at. Really...

Under no load, does an induction motor run exactly at its synchronous speed (i.e. relative field speed) or at a speed that is close to the synchronous speed but slightly less? Thanks for your time.

I first thought that electromagnetic induction disobeyed the law of conservation of energy since there is another current created by another current by changing it (AC). but then there is Lenz law that says when you have yourself an current and also a changing magnetic flux, there will be an...

an 8 pole 3 phase alternator is coupled to a prime mover running at 750 rpm.it supplies an induction motor which has a full load of 960rpm find the number of poles of the motor and the slip i think the induction motor would work as a generator we can find slip by usin s=(ns-nm)/ns where...

Homework Statement Okay, the concept here is to use induction to prove that for n, (f1 x f2 x ... x fn-1 x fn)' = (f'1 x f2 x ... x fn) + (f1 x f'2 x ... x fn) + ... + (f1 x f2 x ... x f'n). 2. Homework Equations / 3. The Attempt at a Solution I solved the initial step, which was quite...

Homework Statement Two coils are place on an iron heart, like in the picture. The top Coil is connected to a galvanometer, the second could be connected to a power source. Homework Equations Will an electric current flow through the top coil when: a) connecting and then...

I have been tought several times that if an asynchronous induction motor is overloaded, so that the rotor speed goes below where the maximum torque point is, the motor will become unstable, and simply stall, even if you unload it. Why does it do that? fx. here...

Hi all, I would like to install Capacitor Bank into my control panel board which contains of few 10HP induction motors. Currently I'm just able to measure the Ampere for every induction motor by using current meter. How to calculate the reactive power for 10HP 3phase 4pole induction motor by...

On another forum the following problem was posted: "Prove with mathematical induction that $\displaystyle \frac{(n+1)(n+2)...(2n)}{2^n}$ is an integer when $\displaystyle n\in\mathbb{N}$ My solution: I chose to write the induction hypothesis $\displaystyle P_n$ after looking at the first...

Homework Statement A bar magnet is moved between 2 coaxial coils A and B as shown in the figure.The end planes of the two coaxial coils facing the magnet due to induction will behave? Homework Equations The Attempt at a Solution My solution: It will induce south pole in A and B...

Homework Statement Here is a question which frequently occurs on on our school test: "Prove Faraday's law of electromagnetic induction on the basis of principle of conservation of energy" I do not really know how to begin.Thanks!

Homework Statement Let U_{n}=\frac{n^{2}}{2^{n}} for every n in N 1) For every n>0 let V_{n}=\frac{U_{n+1}}{U_{n}} a) Prove that \lim V_{n}=\frac{1}{2} b) For every n>0 prove that: V_{n}>\frac{1}{2} c) First the smallest natural number N such that : n\geq N\Rightarrow...

First Post! So I was curious about how I could relate my new found knowledge of electromagnetic inductance on guitar pickups and I came across this on the internet: http://www.sciencebuddies.org/science-fair-projects/project_ideas/Music_p004.shtml#background Which says, "All of these...

Hi, I'm working on an idea and i need some guidance say i have a wire loop of a single wire (not solenoid) the area of the loop is about 1-2 cm^2 now say i change the area of the loop slightly by about 0.1%-0.01% could i measure with today's electronics this slight change of L thanks in...