Questions tagged [electromagnetic-induction]

Filter by
Sorted by
Tagged with
0
votes
1answer
19 views

Analytical expression for the EMF induced in a solenoid due to motion of a permanent magnet

A permanent magnet (cylindrical) of length (l) and radius(r) with velocity v(t) along z-axis as shown in the figure. I am looking for analytical expression for the induced emf in a coil with N turns, ...
0
votes
0answers
18 views

Need Help with Proving Faraday's Law of Electromagnetic Induction with Experiment Results [on hold]

I have recently conducted an experiment measuring emf over time and magnetic field strength over time as a bar magnet fell through a coil. The magnetic field was measured by pointing a magnetometer to ...
0
votes
1answer
21 views

Drone's sufficient engine RPMs initiated by Magnetic Fields

I've seen many videos where magnets are used to initiate and boost RPMs. Most of them are fake, where people are using compressed air at the backstage. Did anyone of you actually tried to challenge ...
0
votes
1answer
40 views

Nature of induced magnetic field lines in cylindrical capacitor

What is nature of the induced magnetic field lines inside a cylindrical capacitor which has a time variant potential gradient across it? For a parallel plate capacitor, its straightforward: the ...
0
votes
0answers
33 views

On a rotating body is induced emf dependent on reference frame?

The magnetic field K is pointing inwards. Why does the induced emf differ between points B and D if the frame of reference is changed from B to A?
0
votes
2answers
44 views

Why can't a current carrying loop (curl of the electric field exists) produce a time varying magnetic field?

If a time varying magnetic field can give value to the curl of an electric field, why not the other way round? That is, why can't an enclosed loop with some emf produced (basically a current carrying ...
0
votes
1answer
21 views

What is the effect of charge of Sun induced on the Earth as compared to gravity?

As we know gravity is a less attractive force than the for of electric and magnetic fields. My question is where does the effect of magnetic field go while gravity has pull on earth. At this point ...
0
votes
1answer
45 views

Is this video about electrical transformers correct?

In this Youtube video, at around 5:10, it shows two graphs, when we have constant increase in voltage on the left, we have constant voltage on the right, but then when voltage stops changing on the ...
0
votes
0answers
21 views

Trouble understanding fractional flux linkage

My question is quite similar to one in the link: Flux linkage inside of a conductor. But I have trouble understanding any of the answers provided there. Specifically my question is the following: I ...
0
votes
1answer
18 views

If a metal rod of length l is moved perpendicularly, in a straight line, inside a uniform magnetic field, will a emf be induced in the rod?

The magnetic flux density is constant, and the rod is being moved inside the field. And if an emf is induced, how does the flux linkage change in this rod? The cross sectional area of this rod ...
0
votes
0answers
8 views

Helmholtz coil construction and working

If I connect Helmholtz coil to ac( 220v, 50HZ) mains then is it means that the field it will generate is alternating field? Then how it generates a uniform magnetic field?
1
vote
0answers
27 views

A travelling field; Feynman lectures on Physics Volume 2

In Feynman's Lectures on Physics, volume 2, Chapter 18 (18-5), we look at the creation of a electromagnetic field, due to a moving infinite sheet of charge, By looking at the Maxwell equations ...
2
votes
0answers
20 views

How do you apply “flux-rule” in free space?

Faraday's law of induction states that, the tangential component of the force per unit charge$^*$; EMF produced in a loop of wire, is equal to change in the magnetic flux through the loop, $$\int_C \...
0
votes
2answers
42 views

Why current flows in an inductor?

If during self-induction the inductor produces a current in opposite direction of that of battery in order to resist the change of current through it then how could the current after some reasonable ...
0
votes
2answers
49 views

Inductor in a DC circuit [closed]

I found this question, I don't understand how could the current through 2R ,immediately after opening the circuit, be less than when the circuit is closed! Shouldn't be an emf from the inductor that ...
0
votes
0answers
15 views

How should I express the force field acting on a ring in Thomson's jumping ring experiment?

I did Thomson's Jumping Ring Experiment with some additional factors added. I used aluminium rings of the same inner diameter, same thickness (at 2 mm), but varying outer diameter (starting from 65 mm ...
1
vote
0answers
11 views

Velocity attained by a Loop with an induced current

A rectangular loop of resistance R is kept at a certain distance from an infinite straight current carrying conductor. The current is suddenly switched off. The problem was to find the velocity ...
0
votes
2answers
41 views

Electrical generators: power balance

Usually power generating synchronous generators are rated at around 85-90% efficiency. Curiosity struck me as of how a generator with field coils can ever go to such an high efficiency. My thought ...
2
votes
1answer
37 views

Current induced from a changing magnetic field

This question is motivated by Problem 7.12 in Griffiths Electrodynamics book. I have already solved the question, so there is no issue with homework policy. Relevant Equations: $$\Phi = \int{\vec{B}\...
0
votes
1answer
26 views

Inductors in Transformers

Why is it the flux change which induces the ac current of primary coil equal to the flux change that primary coil induces on the secondary coil? Is it possible to prove this? slide from video ...
0
votes
0answers
12 views

Is magnetic flux depending on the orientation of ferromagnetic rotor?

I have attached a picture of Reluctance motor setup. When I turn on the AC source, Magnetic flux lines will build up. My question is, will the magnetic flux will be a function of the angle turned by ...
1
vote
0answers
47 views

Time varying magnetic field and induced electric field

Well I would like to start with asking few questions for you to provide a detailed solution and whose details has been clearly mentioned in the above image. It would be helpful if you could clearly ...
0
votes
0answers
7 views

Induced Electric Field due to Infintely spread out, changing magnetic field

If I have a uniform, downward pointing magnetic field which is spread across a very large region and the magnitude of the magnetic field is increasing with time, what is the shape of the induced ...
0
votes
0answers
15 views

Force on a stationary negatively charged conductor in a changing field

If a magnet is brought near a conductor it induces a current in it caused by the movement of free electrons which behave like tiny magnets. But if a magnet exerts a force of attraction on the ...
1
vote
0answers
54 views

Moving iron rod through solenoid [closed]

What effect(s) does a moving iron rod have on a solenoid? Which of the graphs is correct?
0
votes
0answers
8 views

Correlation between the radius of a cylindrical coil with the curl of the electric field induced in that coil

A background of the lab, I am currently working on: I have different sizes of cylindrical coil of wire, each with different radius. I then pass the coil through a near uniform magnetic field and then ...
0
votes
1answer
21 views

Finding direction of induced EMF

How should I find out the direction of the EMF induced in a rod of any length $l$ rotating with an angular speed $w$ in a region of magnetic field (perpendicular to the plane of the rotating rod) ...
0
votes
0answers
25 views

Why the electric field induced in the $\phi$ component, non-zero as compared to the $s$ and $z$ which are zero?

If we take a coil in a uniform magnetic field, move it around to induced some emf around the coil. And so in order to calculate the curl of the electric field induced in cylindrical coordinate system, ...
1
vote
2answers
70 views

Explanation of motional EMF in a rod

Why does an EMF generate across a rod moving linearly in a region of magnetic field constant with space and time? While proving it, we considered the rod to be connected to a conducting rectangular ...
0
votes
1answer
96 views

Explanation of rotational EMF

Why does an EMF $\frac{1}{2}B\omega R^2$ get created across the radius $R$ of a Faraday's disc when it rotates, with angular velocity $\omega$, in a magnetic field constant with both space and time? ...
0
votes
0answers
25 views

Magnet oscillation with coils

I am trying to conduct an experiment in which I will try to find the natural frequency of a cantilever. To oscillate the cantilever, I thought I could use a magnet and a current-carrying coil wire ...
1
vote
2answers
28 views

Electric Field in conductor near Solenoid

My question is essentially a follow up to this question. It's answer says, the mobile charges in the conductor distribute themselves to make E = 0 inside the conductor. But, I don't understand how a ...
1
vote
0answers
16 views

Question about induced current with an axis parallel to magnetic field

I am currently going over a physics test. One of the questions asked if a square loop of wire perpendicular to a uniform magnetic field entering the page has an induced charge if it is spun ...
1
vote
1answer
107 views

Experiment: Magnet falling in a copper/aluminum pipe

We know that when we release a magnet in conducting pipe (aluminum, copper, etc..) it will be subjected to a magnetic force induced by the induced current. This magnetic field will be created in a ...
0
votes
0answers
7 views

Calculation of eddy currents and subsequent heating in a metal, ATEX-rated junction box

We are building a system which will make use of a stainless steel junction box to connect different circuits within it. This will be located in a hazardous offshore environment so we will be using an ...
1
vote
4answers
103 views

Why does inductor current lag the applied voltage at its terminal by 90 degrees?

I studied electromagnetism and I am currently working with Inductors. I could not figure out the physical reason based on electromagnetics on why inductor current lags the applied voltage by 90 ...
0
votes
1answer
30 views

Magnet moving between $2$ separate coils, connected to a circuit

I was thinking about a question regarding a magnet entering a coil when the following thought came: what if we unravelled the middle of the coil such that it splits into $2$ equal parts, and connected ...
2
votes
3answers
143 views

Current in only inductive AC circuit

Current through a LR circuit is given by $$i=i_0 (1-e^{\frac{-tR}{L}})..1$$From here I can observe that as I tend R towards 0 no current flows through the circuit , and current will be 0 when the ...
1
vote
2answers
55 views

What is actually being removed when a metal conductor is grounded?

I found this image earlier this morning, and yes, there are a lot of diagrams/illustrations about this, transferring charges by induction has been introduced since the very beginning of high school ...
1
vote
1answer
47 views

Does grounding set the potential on a surface of a sphere to $~0~$ or the potential due to the charges of the sphere to $~0~$?

I'm understand that grounding sets the potential to $0$, but I'm confused as to which potential it sets to $0$. Let me explain my question: If I have a sphere and I bring a positive charge near it, a ...
0
votes
1answer
40 views

Regarding the use of Ampere's Law

i wanted to calculate $\mathbf{B}$ of these two parallel wires, and i've taken a glance at the correction and i've found out this equation, i tried to understand it but in vain, where do $(x + \frac{d}...
0
votes
1answer
31 views

Electric field due to changing uniform magnetic field

I think this could be a misunderstanding on my part , still I want to clarify this.Suppose in a region of boundless expanse, there is a uniform magnetic field which changes at a rate $\frac{d\phi}{dt}$...
0
votes
1answer
84 views

How to compute the curl of the electric field, experimentally?

In order to experimentally verify Faraday's law and express the curl of the induced electric field, is there any other way to compute the curl without directly working on the cross product (ie working ...
1
vote
0answers
32 views

Investigating the relationship between a changing B field and the curl of the electric field induced

I am currently working on a 12 page lab report on Faraday's law, essentially investigating, how for different magnetic field strength through a stationary loop of wire with N number of turns, effects ...
1
vote
1answer
35 views

What is $v(t)$ in a sliding conducting rail in a magnetic field?

This is problem 7.7c from David J. Griffiths - Introduction to Electrodynamics. A metal bar of mass $m$ slides frictionlessly on two parallel conducting rails a distance $l$ apart. A resistor $R$ ...
2
votes
2answers
106 views

Why doesn't current cancel in a generator?

I am a little confused about the application of Faraday's law in a generator. If we imagine a magnet attached to a wheel (which spins when water falls on it) next to a coil, as the magnet spins around,...
6
votes
4answers
391 views

How is it possible for the induced emf to take negative values in Faraday's Law of induction?

Faraday's Law of induction states that the work done per unit charge by the (induced) electric force along a loop of wire, or the emf, is minus the rate of change of magnetic flux through the loop/...
-1
votes
2answers
59 views

Rate of change of area of a circular loop exiting a uniform magnetic field

The question is to find the variation in induced electromotive force w.r.t to time or put simply $\varepsilon(t)$ for a circular loop being removed from the region of the magnetic field at a constant ...
0
votes
1answer
19 views

Can electricity be generated using a rotating electromagnet and fixed metal plates enclosing it (as opposed to rotating permanent magnet)?

I was wondering , if this be possible , can we make an adjustable electricty generator? If not, why so? Appreciate any responses .
0
votes
1answer
34 views

Potential drop across inductors in DC circuits

The potential drop across an inductor is equal to $L(di/dt)$ where $L$ is inductance coefficient. But according to this in a DC circuit there should be no potential drop across the inductor (because $...