Loop Definition and 1000 Threads

Homework Statement Find the exact magnetic field a distance z above the center of a square loop of side w, carrying a current I. Verify that it reduces to the field of a dipole, with the appropriate dipole moment, when z >> w. Homework Equations (1) dB = μ0I/4πr2 dl × rhat (2) r =...

In NP problems we can cheaply (polynomial time) test if a given input is satisfying, but the difficulty is that there is an exponential number of possible inputs - the question is if e.g. there is a satisfying input. Imagine there is a simple hardware implementation of verifier (e.g. in form of...

Homework Statement I have a circular loop with a radius of 1 m. The center of the loop is located 2 m away from a infinitely long current carrying wire, with ac current I. Find the flux in the circular loop Homework Equations Φ = ∫ B ds The Attempt at a Solution I've found a lot of examples...

Basic Question Alert ! (I need to brush up my basics and need your help) Problem Statement: I wish to make a current carring cable loop to generate a controlled magnetic field. http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/curloo.html As I understand, the magnetic field generated depends...

Homework Statement A 2250 kg airplane makes a loop the loop (vertical circle) at a speed of 320 km/hour. Find (a) the radius of the largest circular loop possible and (b) The force on the plane at the bottom of this loop. Homework Equations F = m*a Centripetal Force = m * (v2)/r "Critical...

Homework Statement A 2400-turn solenoid is 2.4 m long and 10 cm in diameter. The solenoid current is increasing at 1.4 kA/s . Find the current in a 5.0-cm-diameter wire loop with resistance 9.0 Ω lying inside the solenoid and perpendicular to the solenoid axis. Repeat for a similarly oriented...

I am trying to formulate the Current Density for a Loop of wire with a diameter,d, current,I, and an cross-sectional Area of the wire ##\pi(d/2)^2##. With spherical coordinates (radial, azimuthal, polar) ##\bar j## = ##\frac{I}{\pi(d/2)^2}*cos \theta *sin \phi \hat x##...

Let ##P## be a ##U(1)## principal bundle over base space ##M##. In physics there are phenomenons related to a loop integration in ##M##, such as the Berry's phase ##\gamma = \oint_C A ## where ##C(t)## is a loop in ##M##, and ##A## is the gauge potential (pull back of connection one-form of...

Homework Statement A circular coil with radius a is connected with an equilateral triangle on the inside as shown in the figure below. The resistance for each section of the wire is labeled. A uniform magnetic field B(t) is pointing into the paper, perpendicular to the plane of the coil. B(t)...

What is the highest loop order in standard model scattering computations that still contributes a measurable effect seen in past and present particle collider experiments? In other words, to which order are loop corrections necessary for accounting for observed high energy physics? I expect it...

Consider an electric charge Q with rest frame R and a closed conductive loop L with rest frame R'. Q is moving relative to L, and vice versa. In R, the loop is moving and receives no magnetic flux from Q thus no voltage according the integral form of Faraday's law. In R', the loop receives...

Homework Statement Modification: Take two big loops kept on both sides of the small loop at a distance a from the corresponding end of the small loop. Homework EquationsThe Attempt at a Solution The flux through the bigger loop is equal to the flux through the smaller loop, provided that the...

Homework Statement Homework EquationsThe Attempt at a Solution Assuming the current is steady, I = JA, where J is the current density and A is the cross- sectional area ##E = J/\sigma## Can I take ##\sigma ## uniform here ?

Homework Statement A current of 10A is switched off at time t = 0 in a long cable (picture in attachments). It powers a device, with the current return wire having 5 mm separation. A wire loop of dimension 5 by 5 cm is located at a distance 3 cm from the cable. 1) What Emf is induced in the...

suppose, for example, Pre-inflationary universe in loop quantum cosmology Tao Zhu, Anzhong Wang, Gerald Cleaver, Klaus Kirsten, Qin Sheng (Submitted on 22 May 2017 (v1), last revised 4 Jun 2017 (this version, v2)) The evolutions of the flat FLRW universe and its linear perturbations are studied...

Hello! Hopefully someone here can help with this problem: I have a condenser that holds 35 gallons of water to cool the copper coil on my still. I need to know if I can create a closed loop system of cooling water that allows me to avoid running a chiller. I know that there is probably an...

Homework Statement A jet fighter flies in a vertical circle of diameter 1000 m. The speed of the aeroplane at the bottom of this circle is 185 m s-1. For the aeroplane at this point, calculate: Apparent weight Homework Equations Fc = mv^2/r Ac = v^2/r Fn = Fg + Fc The Attempt at a Solution...

Homework Statement A rectangular loop of wire, L = 28.8 cm and W = 15.2 cm, carries a I1 = 2.02 A current and lies in a plane (d = 11.0 cm), which also contains a very long straight wire carrying a I2 = 12.7 A current as shown in the figure below. Homework Equations F=uo*i1*i2*l/perpindicular...

Homework Statement A car of mass m is initially stationary on a smooth track at distance h above the ground. What would be the minimum value of h required in order for the car to remain on the track throughout its journey around the loop of radius r? Homework Equations KE(bottom)>PE (top)...

HI! I'm a student, this question appeared in one of the old tests. I though I had it solved but apparently I must have missed somewhere. Could someone please at least hint me where I went wrong? Homework Statement Thin wire is wound into circular frame with radius ## r = 0.05m ## which...

A new duality between Topological M-theory and Loop Quantum Gravity Andrea Addazi, Antonino Marciano (Submitted on 17 Jul 2017) Inspired by the long wave-length limit of topological M-theory, which re-constructs the theory of 3+1D gravity in the self-dual variables' formulation, we conjecture...

I was doing some integral exercises for getting area under the function. I was doing only more simple stuff, like functions that don't go over the same "x area" multiple times, like a quadratic function. My question is how to calculate area of a loop in an equation x^3+y^3-3axy=0 if let's say...

Homework Statement First of all, this ISN'T homework. This is independent study. I am in a CS program, but I am going through PPP by Bjarne Stroustrup to keep the language fresh. I'm working on one of the last assignment in chapter 4 which is this: Write a program where you first enter a set...

Homework Statement In the circuit shown, find (a) the current in each resistors (b)The power dissipated in each resistor. Homework Equations V=IR, P=VI, KVL and KCL The Attempt at a Solution See attached. I was going to post this in the main section as its really a question about whether you...

Hi, I am new here so hopefully this is the right place to ask a question like this. Forgive me if I have trampled a rule. If I have, please let me know what I should do to ask this question. If you take a wire with a flowing DC current and vibrate it, can it radiate as a radio transmission...

Homework Statement The current loop of the radius b as shown in figure is mounted rigidly on the axle,midway between the two supporting cords.In the absence of the external magnetic field,the tension in the two cords are equal and are T.What will be the tension when a vertical magnetic field B...

Homework Statement A bar magnet is attached to the end of a non-magnetic spring, with spring constant 484−1, as shown in the diagram. The other end of the spring is attached to a fixed force sensor which was zeroed when the magnet was at its equilibrium position, before being zeroed, the force...

Homework Statement I am trying to find out the rate at which I need to pump water into a device generating a specific amount of heat to keep it at a low temperature. I have not taken thermodynamics yet, and so I am trying to use a very basic model. The water is pumped through a copper pipe. I...

1. The problem statement, all variables, and given/known data I was just wondering if a roller coaster can still pass through a loop with less than critical velocity/energy (Also if I'm assuming critical energy correctly). The loop can be of any size yet it must not exceed 5.7g at the entry...

I am trying to understand the magnetic dipole field via loop of wire. The above pictures show how this problem is typically setup and how the field lines are typically shown. The math is messy but every textbook yields the following: β = ∇xA = (m / (4⋅π⋅R3)) ⋅ (2⋅cos(θ) r + sin(θ) θ) The...

Hello! I am having problems with this exercise if someone can please help me. Homework Statement In order to go all the way around a frictionless circular loop of R=2.5 m , how fast must a mass be moving as it exits at the bottom of the loop. 2. The attempt at a solution I am doing this...

Homework Statement Homework Equations ##E_{\operatorname{total}}=E_{kin}+E_g## ##F_{net}=F_N+F_g## ##a=\frac{v^2}{r}## The Attempt at a Solution I've already technically completed question 4 part c, getting an answer of 8168 N downwards (which is what the answers say). However, this is...

Imagine you have a level track with a loop de loop on it. The loop de loop is shaped like a perfect circle. You are inside the cart and approaching the loop de loop. I know that gravity and the normal force both act to produce the centripetal force. However at the very bottom of the track the...

Homework Statement Suppose we have a roller coaster cart of mass m, which may be approximated as a point mass for our purposes. Ignoring friction and air-drag, what is the displacement of the cart as a function of time? It enters the loop with an initial velocity $$ v_0 \hat i $$ and the radius...

First of all, I would like to admit that my understanding of general relativity is limited, though this will hopefully be remedied this summer when I take a GR class. I think we have all seen a sci-fi movie where the characters are stuck in a space where they are trapped in a sort of "warp...

Homework Statement Finding closed loop gain and Ip and In current in op amp Homework Equations - The Attempt at a Solution I started by trying getting voltage divider for points between R1 and R2 as (R2/(R2+R1))Vs and between R4 and R5 similarly. And I'm not sure how to continue on. Any help...

Homework Statement 2. Homework Equations FB = ∫I ds×B The Attempt at a Solution My first guess was that it would not move at all. I understand that there is an induced magnetic field in the opposite direction but wouldn't the induced field produce a current counterclockwise, which, since...

Homework Statement Homework Equations Magnetic flux = integral(B dot dA) line integral(B dot ds) = (u_o)(i_enc) (Ampere's Law) The Attempt at a Solution I can't see how Ampere's law applies because all of the magnetic field vectors along the loop will be perpendicular to that stretch of...

Hello guys, I'm reviewing for the AP physics C exam and in one of my review books I came across this trick called a VIR chart for circuit analysis. It's a sort of weird alternative to the usual Loop Rule. If you haven't heard of it before here it is...

Hey all, I have a question regarding C-Strings. Say I have the following function #include <iostream> using namespace std; int main() { const int SIZE = 5; char cstr1[SIZE] = "Hi"; cout << cstr1; return 0; } This will actually print out the string literal. I'm confused because...

I have a Do loop running which, for some values will become complex, and I want to make it so for these situations, we take the negative root and for others the positive root. In this scenario, I've simplified what I actually have and chose to look at the case where I need it to take the...

Homework Statement A circular loop of radius 0.10 m is rotating in a uniform external magnetic field of 0.20 T. Find the magnetic flux through the loop due to the external field when the plane of the loop and the magnetic field vector are (a) parallel. (b) perpendicular.Homework Equations...

Homework Statement Find the force on the triangular loop in the figure: I am trying to do this in cylindrical polar coordinates, because it builds character. Homework Equations $$\vec{B}(\vec{r}) = \frac{\mu _0}{4\pi} \int \frac{I(d\vec{l} \times \hat{\alpha})}{|\vec{\alpha}|^2}$$ Where alpha...

Homework Statement A 15-turn rectangular loop of wire of width 10 cm and length 20 cm has a current of 2.5 A flowing through it. Two sides of the loop are oriented parallel to a uniform magnetic field of strength 0.037 T, and the other two sides are perpendicular to the magnetic field. (a) What...

Homework Statement A small circular flexible loop of wire of radius R carries a current I. It is placed in a uniform magnetic field B. The tension in the loop will be double if A) I is doubled B) B is halved C) r is doubled D) both B and I are doubled. Homework Equations The Attempt at a...

I have some trouble fully understanding the PLL block diagram shown below in the figure. The PLL circuit is used to generate currents (i alpha and i beta) which are in phase with the positive fundamental sequence of the voltage. I am using the book "Instantaneous Power Theory and Applications...

Homework Statement A single-turn wire loop produces a magnetic field of 41.2 μT at its center, and 5.15 nT on its axis, at 20.0 cm from the loop center. Find loop raidus and current. Homework Equations F = qv x BThe Attempt at a Solution I tried to use the above equation, but could not figure...

Hi the difference between a loop antenna and a magnetic probe (B-Probe) is only that the loop antenna works in far field and B-Probe works in near field? The standard features of magnetic antenna (antenna factor, impedance matching, radiation patterns, efficiency, ecc) have the same definition...

Homework Statement ##G_{OL} = \frac{5}{s}## ##G_{CL} = \frac{KG_{OL}}{1+KG_{OL}}## Homework EquationsThe Attempt at a Solution It's pretty easy when the equation is so simple ##G_{CL} = \frac{K\frac{5}{s}}{1+K\frac{5}{s}}## ##G_{CL} = \frac{5K}{s+5K}## If the open loop equation is really...

Homework Statement The figure shows a 10-cm diameter loop in three different magnetic fields. The loop's resistance is 0.10 Ω. For each case, determine the induced emf, the induced current, and the direction of the current. Homework Equations Faraday's Law: εinduced= - (ΔΦb/Δt) = - A ⋅ ΔB...