Coil Definition and 864 Threads

Homework Statement A 44.0 -turn, 3.90-cm-diameter coil with R(resistance) = 0.510 surrounds a 2.40-cm-diameter solenoid. The solenoid is 16.0 long and has 240 turns. The 60 Hz current through the solenoid is I(solenoid)= 0.530Asin2\pift. Homework Equations Find the value of I(coil)...

[SOLVED] Average Current Through A Coil Over An Interval Homework Statement The problem comes from a homework assignment I have. It has to deal with average current flowing through a wire over an interval. It is stated as follows: A five-turn circular coil of radius 15cm is oriented with its...

I have noticed there are different Inductance formula's for a various types of air coils & there design, single layer spiral, flat wound spiral, multilayer etc. My question is for the design of Jumble wound --- Random wound air core coils: What is the Inductance formula for a Jumble...

Homework Statement A step down transformer produces a voltage of 6.0 V across the secondary coil when the voltage across the primary coil is 120 V. What voltage appears across the primary coil of this transormer if 120 V is applied to the secondary coil? Homework...

[SOLVED] EMF problem - Current in Coil Homework Statement A small square coil is located inside an ideal solenoid at the center with its plane oriented perpendicular to the axis of the solenoid. The resistance of this coil is 2.00 \Omega and each side is 4.00 cm long. The solenoid has 125...

please, i want to be sure of my password and user name can it be posted to email? also, idon't know how to submit questions can the guide lines be posted as well? Thank you. A rectangular coil, carrying a current of 400pie amperes, lies in the z=0 plane with its corners at the points...

Homework Statement A long straight wire on the z-axis carries a current of 3.0 A in the positive direction. A circular loop in the xy-plane, of radius 10 cm, carries a 5.0-A current, as shown. Point P, at the center of the loop, is 25 cm from the z-axis. A circular coil of four turns, 2 cm...

Homework Statement You hold a wire coil perpendicular to a magnetic field B. If the magnitude of B increases while its direction remains unchanged, how will the magnetic flux through the coil change? Check all that apply: The flux is unchanged because the position of the coil with...

How do resistance and speed of a coil in pendulum motion in a magnetic filed affect the induced voltage and the decay of Potential Difference? Details: Q1 When the speed of a coil is kept constant and a 3.3ohm resistor is added to the circuit of which the coil is a part of, the induced...

Homework Statement A bar magnet with magnetic dipole moment 0.51 A m^2 lies on the negative x-axis, as shown in the diagram. A compass is located at the origin. Magnetic North is in the negative z direction. Between the bar magnet and the compass is a coil of wire of radius 1.5 cm, connected...

Is there a theoretical limit to the time constant of an electric motor? I was think, if inductance is simply the conversion of current into the magnetic field, and if increase in resistance limits that current for a given power supply, that having a higher time constant would in effect allow...

Hi. This is a simple one (I think): We all know a swing, or simple mass on a spring, moves in harmonic motion, and has a specific resonative frequency. We also know that the RCL circuit (which includes a coil and a capacitor) reacts similarly to an external oscillator, also with a specific...

Homework Statement A magnetic field is perpendicular to the plane of a single-turn circular coil. The magnitude of the field is changing, so that an emf of 0.91 V and a current of 3.2 A are induced in the coil. The wire is the re-formed into a single-turn square coil, which is used in the...

Hi! This is my first post on this forum, and I have two questions. First of all I'd like to mentoin that my math knowledge is at high school level + some basic calculus. Ah, and I haven't learned about (partial) differential equations yet. My physics skills go only as far as electromagnetism...

Homework Statement In each of two coils the rate of change of the magnetic flux in a single loop is the same. The emf induced in coil 1, which has 200 loops, is 2.67 V. The emf induced in coil 2 is 3.78 V. How many loops does coil 2 have? Homework Equations E=-N(delta Phi/delta t)...

Is the same inductance formula valid for a coil made of hollow tubbing that for a solid wire made , with both having the same width?, and supposing that a high frequency current flows through it whats the skin effect influence on the result

Air cooled coil electromagnet ? Hi. I'm a (very) Junior researcher I'm trying to biuld a solenoid electromagnet (air bore, not metal), But I need it in a specific size and most important I have to have it AIR COOLED (by fan or compressed air). Does anybody know if such an electromagnet...

Hello All, I'm making a long coil for some experiments and I want to put some tap points onto the coil without actually cutting the wire. I was wondering if anyone knows of a simple way to do it? The coil is made out of insulated 22 gauge wire (regular not mag wire) wrapped on a core that...

[SOLVED] pls HELP me There is an electronics competition, so can somebody tell me if there is something better than Tesla coil. The opposition is going to have a demonstration with a Tesla coil. What is your suggestion? What should I construct against the Tesla coil?

Homework Statement A long, solonoidal coil with 2000 turns produces a B field pf 3mT at its center when a current of 1A flows through the coil. If the cross sectional area of the coil is: 2*10^-3 m^-2, and the field is uniform throghout the solonoid, determine the self inductance of the oil...

Say I've inserted a north pole of a bar magnet into a toroidal coil. When the bar is moving there will be an induced EMF in the coil which will lead to a magnetic field that opposes the initial magnetic field. From what I understand the B field in the toroidal coil is circular inside the coil. I...

I need only one photon from a coil and battery set up. Anyone know how I can get just one photon? e.g. 1) slowly increasing ramp voltage that spits out single photons slowly? 2) Send a tiny voltage in by pushing a switch? 3) Have many windings or just a few? Any clues...

can anyone help with me understanding the physical mechanisms that determine the current that flows through a MOVING coil immersed in a magnetic field when a fluctuating voltage is applied across the coil? Also I need to find a Differential Equation that describes the behaviour of the current...

I am designing an electromagnet and need a strong field strength. I have came across a few different ways to wire the coil and am curious which way produces the strongest dipole electromagnet. The coil is to be wound around a cylindrical steel core. The first way is what I think is the most...

hi, I have tested impedance of transformer coil and I found out that if I would like to have smaller input impedance then I have to reduce the diameter of magnetic wire. I understand that If i reduce the cross setion of the wire then I will reduce the DC resistance. I don't understand...

Homework Statement Tungsten wire has an emissivity of 0.35. A tungsten filament in a light bulb can be considered to emit light only from the sides of the filament (consider it a cylinder... they are usually wire "cylinders" wrapped into coils.). If the operating temperature of the filament...

On a particular dynamo, the rotating coil has 500 loops, each of area 2.5x10-4 m2. The magnetic field can assumed to uniform and of magnitude 0.400T. When the bicycle is ridden at a particular speed, the coil rotates with a frequency of 8Hz. What is the maximum emf produced? What is the average...

A magnet will induce EMF when it passes through a conducting coil. Where does that energy come from? Does the coil do work on the magnet somehow? The B field induced in the coil should be parallel to the magnet's motion, so I would think it could not slow the magnet's progress. Does the magnet...

Hi I wondered if anyone could explain as to how actually the whole process of transformation of voltage happens. I know the equations involved but can't get them together to reach a conclusion. When a.c. is passed throught the primary, a flux is induced in the core, which travels to the...

Homework Statement A square, single-turn wire coil L = 1.13 cm on a side is placed inside a solenoid that has a circular cross section of radius r = 2.77 cm, as shown in the figure below. Basically a big circle with a square in the center. The solenoid is 20.0 cm long...

Is the incoming flux (first peak) equal in magnitude to the outgoing (second peak) flux? Why? A magnet was dropped through a solenoid, this experiment was completed twice, a graph of Voltage (V) vs. Time (t) was made for each experiment. The area under each curve is defined to be equivalent to...

Homework Statement Given: u_0 = 1.25664e-6 A 2 m long large coil with a radius of 14.6 cm and 320 turns surrounds a 4.2 m long solenoid with a radius of 4.6 cm and 7700 turns. The current in the solenoid changes as I = I_0 sin (2pi*f*t) where I_0= 30 A and f=60 Hz.Inside solenoid has...

Hello ALL, I have a question about magnetism and generating electricity in a coil from a group of another coils that are alternately switched on/off (cascade). Would a current be generated from a group of coils that are switched on and off in sequence, having another coil parallel to them...

any of you every attempt to design and build a tesla coil. I would love to build one . Can any of you share your experiences when you first begin to construct the Tesla coil and how long did the project take? What materials do I need. Do you have to be an electrician to build a tesla coil

Cooler than the electric guitar http://www.hauntedfrog.com/gt/movies/2007/duckon/SingingTeslaShow.html"

part 1: A galvanometer has a coil with a resistance of 81 W. A current of 131 mA causes full scale deflection. Calculate the value of the series resistor that is required in order to use the galvanometer as a Voltmeter with 40 V full scale. so to make a voltmeter, the galvanometer and...

What exactly is the solenoid shape? Is it just the shape of the coil with the core inside or do they refer to the shape of the magnetic field surrounding the coil?? Is this the solenoid, just the coil? Or are they talking about the magnetic field that surrounds the coil?

I was reading there that if you wind a piece of metal wire into a coil it creates a magnetic field. Does this wire have to have current running through it? I know that a changing electric current creates a magnetic field but how does winding a piece of metal wire into a coil create magnetic flux?

a coil of wire is connected to an uncharged capacitor in a magnetic field... Homework Statement A 10-turn coil of wire having a diameter of 1.0 cm and a resistance of 0.20 ohms is in a 1.0 mT magnetic field with the coil oriented for maximum flux. The coil is connected to an uncharged 1.0...

If I place a pipe filled with WATER inside of a coil and then half filled pipe of same material, does the inducatnec change? Will the change be able to be observed using multimeter? any ideas?

Homework Statement The radius of a single coil of wire is 0.22m. It carries a 200 A current that flows clockwise. A long, straight wire carrying a current of 310 A toward the right is located 0.05m from the edge of the coil. What is the value of the magnetic field at the center of the coil...

The diagram shows a DC electric motor containing a rectangular coil of 20 turns and of length .50m and width .40m The coil is pivoted so that it can rotate freely on an axle. The coil is shown lying horizontally in a magnetic field of uniform stength .60T. A current of 3.5A is passing through...

Driving a coil...Voltage drive..? Current drive..? Hi Guys As the title...I am now having a 10 turns coil, does it really matter that I drive it with sinusoidal voltage signal or a sinusoidal current signal? Will it affect the response of the coil? (like resonance frequency, Q factor...etc)...

A circular conducting coil with radius 2.61 cm is placed in a uniform magnetic field of 0.827 T with the plane of the coil perpendicular to the magnetic field. The coil is rotated 180° about the axis in 0.222 s. (a) What is the average induced emf in the coil during this rotation? (b) If the...

The component of the external magnetic field along the central axis of a 50−turn coil of radius 5.0 cm increases from 0 to 1.0 T in 4.3 s. (a) If the resistance of the coil is 2.9 Ω, what is the magnitude of the induced current in the coil? (b) What is the direction of the current if the axial...

A 40-turn, 4.0-cm-diameter coil with resistance R=.40 ohms surrounds a 3.0-cm-diameter solenoid. The solenoid is 20 cm long and has 200 turns. The 60 Hz current through the solenoid is I = I_0 * sin(2pi*f*t). What is I_0 if the maximum current in the coil is 0.20 A? Basically, there is a coil...

Dear all, I know that I can create a uniform field using the design of a Helmholtz coil with an air-core. However, if I use a ferrous core like iron, will I still be able to create a uniform field under the same conditions? Also, how is the equation for the magnetic field, B, changed when...

Hi, This problem confused me the first time around, but I think I've got it. I just want a confirmation that my reasoning is correct. I know I have the correct answer, but what is important is the method of arriving at it. Homework Statement A wire is being wound around a rotating wooden...

What is the principle of "tesla coil'?? What is the principle of "tesla coil'? What is different between "tesla coil' and 'high-voltage transformer"? Thank you in advance!

Hi, I'm kinda new her, so I hope this is the right place to post this. English is not my native language, so you might experience some spelling error:) I am working on a project that my teacher assigned med the other day, were I am supposed to find out how i can measure the movement/velocity...