Induced Definition and 925 Threads

Homework Statement Homework Equations emf = i (induced) R emf = - d(Ф)/dt Ф = B (dot) A B = μi/(4piR) The Attempt at a Solution emf = - d(Ф)/dt emf = - d( B (dot) A )/dt emf = - d[ (μi/(4piR) * A ]/dt, A and B are perpendicular Really not sure how to proceed from here as there are...

Homework Statement Homework Equations Faraday's and Lenz' law. emf = -d(ф)/dt The Attempt at a Solution The current is increasing upwards during that time interval. Thus, by Right-Hand-Rule, the magnetic field goes into the page at the loop. Lenz' law says that the loop's induced emf...

Homework Statement A simple pendulum with bob of mass m and conducting wire of length L swings under gravity through an angle 2 theta. The Earth's magnetic field component in the direction perpendicular to swing is B. The maximum potential difference induced across the pendulum is Homework...

Homework Statement A square conducting loop lies in the xy plane of an xyz coordinate system. The loop is in a uniform magnetic field that points in the positive z direction and is decreasing at a rate of 0.070 T/s. What are (a) the magnitude of the induced EMF in the loop and (b) the direction...

Homework Statement It's Problem 6.6 on this page: http://web.ece.ucdavis.edu/~lxgliu/eec130a/2012winter/hw9s.pdf It has the solution and everything. I don't understand part (b) though. Homework EquationsThe Attempt at a Solution [/B] For part (b), I thought the direction of the induced...

A Power supply is connected to a parallel circuit with resistance R, there are three wires connected in parallel where the voltages would be the same,however, the current would be dived based on the number of wires and the resistance is the same. What would happen if wire (c) was placed in a...

I'm messing around with Faraday's Law of Induction, and I will be using two magnets attached either side to a small bar inside two coils of copper wire, which I spin to induce a current. The design is basically this: http://amasci.com/amateur/coilgen.html My question is, what shape for the...

I am having trouble understanding a process in the electric motor. using this website as a frame of reference (http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/mothow.html), as an electric current is passed into that magnetic field, shouldn't the current also be creating a magnetic field, and...

Homework Statement . A circular coil of radius 5.0 cm and resistance 0.20 Ω is placed in a uniform magnetic field perpendicular to the plane of the coil. The magnitude of the field changes with time according to B = 0.50e-20t T. What is the magnitude of the current induced in the coil at the...

1. A very large loop of metal wire with radius 1meter is driven with a linearly increasing current at a rate of 200amps/second . A very small metal wire loop with radius 5centimeter is positioned a small distance away with its center on the same axis (the loops are coaxial). The small loop...

Homework Statement The armature of a simple motor consists of a square coil and carries a current of 0.55 A just before it starts to move. The coil is positioned perpendicular to a magnetic field. Explain briefly why the current falls below 0.55A once the coil of the motor is rotating...

Homework Statement [This is the best image I could find] The link on the bottom part of the rails is now removed creating two parallel wires that are not connected (so no longer U shaped but just two rails). Now a wire of length L, mass m and resistance R slides without friction down parallel...

Homework Statement A magnetic field passes through a circular loop of radius 14 cm and makes an angle of 65° with respect to the plane of the loop. The magnitude of the field is given by the equation: B = (1.25t2 - .500t + 4.00)T. a) Determine the voltage induced in the loop when t = 2.00 s...

Homework Statement A long, straight wire as shown below carries a constant current I. A metal bar with length L is moving at a constant velocity V as shown. Point ‘a’ is a distance ‘d’ from the wire. a) Derive an expression for the EMF induced in the bar. b) Which point ‘a’ or ‘b’ is at a...

Homework Statement I have the strength of the magnetic field, B, the time, Delta t, a circle formed ring with the diameter, d. I should calculate the induced tension, when the surface is (a) parallel to the B field (b) 50 degrees on the B field Need help to solve it (symbolic if...

Here is the question that we have been debating for the past day or so: Take a conducting cubic box and center a conducting sphere with charge +q inside of it. Will the induced charge density on the sphere be uniform or not?My gut instinct is no. The cube and sphere have different symmetries...

I have a confusion about the energy effects of current induction. Suppose I place a coil of wire near a long, high-voltage AC power-line. The changing current and hence, the changing magnetic field it produces will induce current in my coil. Then, I can connect the coil to a resistor and get...

Homework Statement [/B] Suppose, there is a 'constant' magnetic field ##B## in the upward direction. A loop of conductive wire(XYZ in the picture, which is connected to a closed circuit with resistance R) is placed horizontally on it. The area of the loop is being increased with time. Will...

Homework Statement This is a simple inquiry, based on what my textbook has told me. "...the amount of induced current also depends on the angle of the conductor in relation to the external magnetic field. The induced current is at a maximum when the plane of the loop is parallel to the...

Faradays law tells us that a change in flux induces an emf. Now consider the phenomenon of motional emf. It is observed across the ends of an open conductor (ie one which is not in a circuit). It is always discussed in connection to faradays law. Where is the change in flux in the case of a...

Homework Statement An infinite wire carrying a constant current ##I## in the ##\hat{z}## direction is moving in the ##y## direction at a constant speed ##v##. Find the electric field, in the quasistatic approximation, at the instant the wire coincides with the ##z## axis. [Answer...

Hello, Suppose you have a sphere, traveling at u = 0.99 c along the x axis in our frame S. I was wondering how the sphere's metric changes due to Lorentz length contraction. Obviously at the rest frame of the sphere, it will appear as a sphere. However on S the sphere will appear as an...

Homework Statement Imagine a uniform magnetic field, pointing in the ##z## direction and filling all space (##\vec{B} = B_0\hat{z}##). A positive charge is at rest, at the origin. Now somebody turns off the magnetic field, thereby inducing an electric field. In what direction does the charge...

In electrostatics, ∇ × E = 0 so E that is a conservative field and there must be sources of E from which E flows. We know that this sources are the electrical charges given by Gauss' Law. But when B changes in time, ∇ × E = - ∂ B / ∂t. Now the Gauss' Law no longer applies and if there are not...

Homework Statement Three conducting capacitor plates are kept horizontally, above each other with a gap 'd'. If a charge ##+1\mu C## is kept on the middle plate what is the charge on the plates? Homework Equations (This question is theoretical) The Attempt at a Solution My textbook gave the...

Homework Statement A 40 turn circular coil of a 4.0 cm radius and a total resistance of 0.20 Ω is placed in a uniform magnetic field directed perpendicular to the plane of the coil. The magnitude of the magnetic field varies with time as B = 50*sin(10π*t) mT where t is measured in s. What is...

I have been studying electromagnetism this year and we have spoken about Faradays law of electromagnetic induction and eventually how the emf induced is equal to the negative time rate of change of magnetic flux I noticed however that all examples include a time varying magnetic field, which...

Im having trouble convincing myself that a charge located anywhere inside a conducting sphere will create an induced charge on the surface of the sphere with an electric field that is completely uniform. This doesn't make much sense to me. Also same with how the electric field inside solid...

I have a confusing example that I'm studying, I tried to figure out the direction of induced current. But the right hand rule would tell me there isn't, but there has got to be since there is change in flux?! Here is the example: The gray bar is the conductor that is moving through a...

to calculate emf i can use the flux rule -d(magnetic flux)/dt or the lorentz force line integral across the circuit. Is there a gudeline to follow for knowing when to use either (or both) of these methods? Thanks :D

Homework Statement Consider the loop in the figure below. What is the maximum induced emf in each of the following cases if A = 600 cm2, ω = 31.0 rad/s, and B = 0.490 T? Rotating about x,y,z? Homework Equations Faraday's law The Attempt at a Solution This should be relatively easy since the...

Homework Statement The current in a solenoid (you may treat it as a long solenoid of length 2.0 m, turns, and radius 0.5 m) is decreasing at a rate of 1.7 A/s. What is the EMF at a point .35m inside the solenoid? Homework Equations B=N(mu_0*I)/(2a) where B=magnetic field, N=turns per...

Homework Statement When Cl = 0.9, find the difference in induced drag for a rectangular wing of 36-ft. span and 6-ft. chord and a tapered wing of the same area, the tapered wing having a 6-ft. chord at the root, the leading and trailing edges being tangent to a circle of 2-ft. radius at the...

Suppose there is an uniform magnetic field along z-direction. Now someone turns off the field. Then there will be an induced electric field. Can anybody draw this induced electric field lines? I know the electric field will curl around. But where will be the centre of that curl. Do the electric...

Homework Statement I actually have three problems that have one thing in common that I don't understand. I will try to shortly describe all of them: 1. We have two perpendicular planes. (See Attachment: sketch1.png) The idea is to describe the electric potential in space. Now you can believe...

why does induced emf change in case of generators but remains constant in case of moving conductor?

Homework Statement A rectangular loop of wire, of sides 5 and 3 cm moves away from a a long straight wire at 4ms-1 carrying a current of 2 amps. What is the EMF induced in the moving loop, when the near side of the loop is 3cm away from the wire? Homework Equations B = μ0I/2πr EMF = -dΦ/dt...

A simple experiment of pushing magnet bar into solenoid & pulling it out from solenoid. If galvanometer is used to measure magnitude of induced current, galvanometer will show greater deflection when the bar magnet is pushed into the solenoid but the deflection will be less when the magnet is...

Hello all, I am M.Tech student and doing my dissertation on friction stir welding stimulation in ANSYS Mechanical APDL. I need to simulate residual stresses induced during welding using ANSYS. How can I do the same, please reply. I am a beginner in ANSYS. I don't have much knowledge of ANSYS

Hi, I am trying to derive the path length of a charged particle in a B-field. I am assuming the particle will travel a distance L along the applied field. Using the following equations for the path length of a helix and gyroradius: Helix defined as [a*cos(t),a*cos(t),b*t] for t on [0,T] has...

Homework Statement After induction, the cola can has +ve charges on one end and the -ve charges on the other end. Now when we touch cola can with our hand, why does electrons start flowing through it and get grounded. Doesn't the +ve charges on the one end of the can attract the -ve...

Hello, I have a conducting copper ring of inner radius a and outer radius b. point charges Q pass through the centre of this ring for time dt. so I guess I'm suppose to get a step function of induced current or something similar. 1)what is the equation relating the charge Q to the...

Homework Statement (a) The metallic rectangular loop of length b and width a (ABCD) is mounted in an assembly, which allows it to be rotated about an axis bisecting AD and BC. The plane of the loop makes an angle θ to the horizontal and a uniform magnetic field B is applied vertically...

In a DC circuit(Yes, keep going), when current starts to flow, and that current needs a bit of time to stabilize to its maximum value. Since there is change in current(increase) there is an increasing magnetic field, a changing flux... that will induce a -V to the circuit. Eventually when...

Homework Statement A circular coil has N equal loops with diameter C. Each loop has resistivity η and diameter d. There is a field on the central axis of B(t) = B_0 sin(ωt). Find the induced current (ignoring other fields) Homework Equations emf = -d/dt * flux(t) i = emf/R R = η*l/AThe...

Hey everyone I'm new here and this is my first thread, although i have great interest in chemistry and physics my knowledge of these fields is very basic( I'm graduated in economics) so don't be surprised if i ask something that may look silly. so here are my firsts questions. -Is it...

Hi all, I am looking into induced electric fields by changing B fields inside layers of dielectric. For example, if a block of several layers of a dielectric material is placed inside a capacitor plate, the E fields inside each layer is shielded depending on the relative permitivitty...

Hello here is a problem that we want to find induced voltage in two different questions. 1-here is part (a) solution: question 1:why we get integral in all space of conducting rail instead of bar space?(Area of bar)for example if we enlarge the space and set bar fix again induced voltage...

This thing has confused me for long .I have not come across any satisfactory answers on my own or while browsing through the internet. Everybody has seen the example of a rod moving while on parallel rails, with magnetic field perpendicular to the plane of loop formed by rod and rails...

Homework Statement There's a magnetic field B in +\hat{z}. A rectangular loop is lying in the xy-plane. Three sides are static, the 4th one is moving with velocity v along the direction of +\hat{y}, making the rectangular larger and larger. The length of this moving side of the rectangle is L...