Coils Definition and 188 Threads

Homework Statement In a compact cicrcualr coil "A" (radius R= 25cm),formed by N=150 loops of wire, flows I=10A current. There's another compact circular coil "B" over "A"(radius r= 1.5 cm, loops n= 30) coaxial with "A" distant X ,in which i= 4A flows . in the same direction of "I" (look...

Homework Statement In a compact cicrcualr coil "A" (radius R= 25cm),formed by N=150 loops of wire, flows I=10A current. There's another compact circular coil "B" over "A"(radius r= 1.5 cm, loops n= 30) coaxial with "A" distant X ,in which i= 4A flows . in the same direction of "I" (look...

Hello guys, I am curious about the effects of increasing the number of coils on the armature of a DC electric motor. Say if I switch from a coil from 80 turns to one with 160 turns (made of the same material) would the rotational speed of my motor decrease for the same voltage? I had several...

Two coils have the same number of circular turns and carry the same current. Each rotates in a magnetic field in a setup similar to the square coil in the figure below. Coil 1 has a radius of 5.5 cm and rotates in a 0.17 T field. Coil 2 rotates in a 0.42 T field. Each coil experiences the same...

Ok, you know those flashlights that you shake to charge the battery? I'm no physics major, but I get the basic idea. The magnet is passed through the coil, creating an electrical current. So here's my question: Imagine I changed the structure of the coil a bit. If I take a series of magnets...

Working in CGS units... hence i don't know if my answer is right or wrong anymore... It doesn't 'look' right Homework Statement Two coils are placed at l and -l on the Z axis as in the figure. They both carry a current I in the same direction (anticlockwise). Both have a radius of a. (Setup...

A coil has a resistance of 2.10 ohms. The potential difference across the coil is 11.6 V at an instant when the current through the coil is 5.00 A and is decreasing at a rate of 36.0 A/s. What is the coils inductance? I thought i could use the equation X=2pi fL to solve for L.. but i am...

Homework Statement For coupled coils in this arrangement (illustration attached), show L_{eq} = \frac{L_1 L_2 - M^2}{L_1 + L_2 - 2M} Homework Equations KVL (mesh analysis) The Attempt at a Solution As you can see, I get to a final answer - which is not exactly the same...

I am currently working on a research project, and need an equation or method to find the magnetic field strength produced by any number of helmholtz coils, and not just on the central axis, but at any position in the space around them. Can anyone help me out? Thanks

I watched a home video about the Tesla coil and saw the electric bolts...i thought the guy was standing kinda close to this thing but never got struck. Is there a limit to how far away the bolts of electricity can go from the coil? They looked pretty random.

I have a 555 out put connected to a coil and i get the frequency i need. But now i need the 555 to power more coils. How should i connect the coils to keep the same frequency. In parallel or Series? The 555 will not directly power the coils. It will switch a Mosfet and that will provide the...

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...

Hi everyone, Just a quick question that was bugging me... If i was asked to draw the voltage output vs time of an induction coil...would it be absolute value sine curve?? Secondly i absolutely don't understand how in Hertz experiment, what the sparks jumping across have anything to do...

Homework Statement How do I take the first and second derivatives of the helmholtz equation? The equation is as follows: Bx= ((uR^2NI)/2) * ( [1/((x+a)^2+R^2)^(3/2) ] + [1/((x+a)^2+R^2)^(3/2) ] ) heres what I have to prove First Derivative...

Our teacher wants us to construct a speaker that can provide sound (that can be heard from anywhere within the classroom) when connected to wires that are hooked up to some sort of device. I'm unsure of where to start and where to get the supplies. Since we are on the magnetism course, I know...

Hi, Just had a bit of a heated discussion with a friend of mine about electricity meters and I decided to get some info from you chaps so I can promptly add some ammo to my argument next time we meet! The claim is that you will get a low resistance reading between phase and neutral meter...

Homework Statement Coil 1 has L=25mH and N=100 turns. Coil 2 has L=40mH and N=200. The coils are rigidly positioned with respect to each other, and their mutual inductance is 3.0mH. A 6.0mA current in coil 1 is changing at 4.0 A/s. (a)What magnetic flux Phi12 links coil 1 to coil 2, and what...

We have done a simple experiment on AC transformers. Given: AC Supply. Big primary coil. Smaller secondary coil. Even smaller metal rod. (They all fit into each other) Voltmeter What we did: Connected AC supply to the primary coil. Voltage kept constant at all times Secondary coil was placed...

Can i get some help with this problem? This problem deals with the basic loop configuration you will use in the laboratory to construct a metal detector. Two concentric circular coils of wire lie in a plane. The larger coil has 49 turns and a radius of a = 7.90 cm. The smaller coil also has 49...

To find the emf generated by two ten turn coils, the planes of which are at 60 degrees in a radial magnetic field B=Bcos(theta)sin(omega*t) in the direction Ar, that rotates with omega rad/sec at the instant when the coil A1A2 makes an angle alpha with the plane of the maximum flux density...

Hi..I am new here and I am really thankful for any help that I may get :blushing: I am stuck in a problem of mutual inductance. It seems fairly simple, yet I cannot get the correct answer. Two coils are close to each other. The first coil carries a time-varying current given by I(t) =...

An object is attached to the lower end of a 100-coil spring that is hanging from the ceiling. The spring stretches by 0.160 m. The spring is then cut into 2 identical springs of 50 coils each. Each spring is attached between the ceiling and the object. By how much does each spring stretch?

Hello everyone, In my continuing pursuit of understanding of oscillator circuits, I came up with this question and was wondering if anyone here could give me some insight on this. I drew a picture to help me explain the idea but I would like to know what would happen if you have an inductor...

Hello, I am teaching myself about oscillator circuits and I was wondering if someone could help me understand if it is possible to make a coil that will resonate at a natural frequency. I was reading some articles about experiments Nicola Tesla performed and the document I read (don't...

Hi, I have a quick question. I was just wondering which type of coil is best for inducing electricity. If I pass a magnet over one end of the coil, would a metal core help more current to be induced or would an air coil be better? Thanks, Jason O

*Sigh*. I'm embarrassed to ask this question because it seems like a silly question. But at the same time, if I don't ask, I don't know how else I'll find out the answer. I have some documentation for work that says, "The relays are 110 V AC coils..." Believe it or not, that snippet is all...

Hi I am currently involved in building a linear motor which is based around the coil gun principle. I am having trouble understanding the equation for force used to desribe the coilgun's action. namely: Fx = I1*I2*dM/dX Fy = I1*I2*dM/dX Here we are considering two coils of wire...

Ok. say you have a transformer hooked up to two AC generators. They each produce the same amount of voltages. For the primary coils on the transformer (the 2 generators..) one is coiled 100 turns and the other 10 turns...the result? Continuation of question... now assuming that this means...

Hey, Any help will do: A square coil and a raectangular coil are each made from the same length of wire. Each contains a single turn. The long sides of the rectangle are twice as long as the short sides. Find the ratio t(tau) square/t rectangle of the maximum torques that these coils...

Can we please imagine that a sphere Neodymiun magnet with a diameter of one inch was suspended or leviated, reducing friction to none, then we put this magnet inside an acrylic tube that created a vacuum by pumping out all the air out allowing the sphere to spin at enormous velocity with very...

Two coils are wrapped around the same cylinder form. When the current in the first coil is decreasing at a rate of -.242A/s, the induced emf in the second coil has a magnitude of .00165 Volts. What is the mutual inductance? What I did: E_2 = -M(\frac{d_i_1}{d_t}) .00165/-.242 = -M...

Hello, I have kind of an odd question here. I was wondering how to make an electric coil that will naturally resonate at a perticular frequency. I am a novice when it comes to the associated physics so I'm hopeing that someone can explain this to me. I also have another related question. I...

Hello, I have kind of an odd question here. I was wondering how to make an electric coil that will naturally resonate at a perticular frequency. I am a novice when it comes to electronics so I'm hopeing that someone can explain this to me. I also have another relate question. I heard...

hello, here is my second message.(and my English is still very bad) I don't understand these 3 little experiments(we need Helmholtz coils and a Hall Effect probe) I know I have to draw a graph for each situation but I can't interpret the difference between the theory and the experiment...

I have been driving myself crazy trying to figure out this problem, for a while now. I just can't get the right answer. should the number of turns be multiplied or divided by the radius? Please help me out. Two circular coils, concentric and lying in the same plane, produce magnetic...

How do I figure out how much electricity would be generated by dropping a magnet down a coil of wire? What are the specific variables that would determine this? Is the number of coils more importants than the thickness of the wire and If it does generate electricity what's the best way to store...

Hello everyone, I have a little practical question. I would like to create a weight of about 10kg-250kg. A software programm should be able to control the actual weight. Does anybody know a good physical way to do that? I thought of coils using Lorentz but I'm not quite shure. Any help is...

Hi, I am building a vibrating sample magnetometer (VSM) and I have all the components except for the detector induction coils and sample holder. Any ideas where I could get the coils (for cheap)and what to make the sample holder out of? The induction coils have to have an axial length and...