# What is Arc: Definition and 485 Discussions

An electric arc, or arc discharge, is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma; the plasma may produce visible light. An arc discharge is characterized by a lower voltage than a glow discharge and relies on thermionic emission of electrons from the electrodes supporting the arc. An archaic term is voltaic arc, as used in the phrase "voltaic arc lamp".
Techniques for arc suppression can be used to reduce the duration or likelihood of arc formation.
In the late 1800s, electric arc lighting was in wide use for public lighting.
Some low-pressure electric arcs are used in many applications. For example, fluorescent tubes, mercury, sodium, and metal-halide lamps are used for lighting; xenon arc lamps have been used for movie projectors. Electric arcs can be utilized for manufacturing processes, such as electric arc welding and electric arc furnaces for steel recycling.

View More On Wikipedia.org
1. ### B Would the Giant Arc be visible from a hypothetical exoplanet?

I recently watched History of the Universe and they talked about the Giant Arc, a large scale structure that spans 3.3 billion light years long, exceeding the hypothetical limit of 1.2 billion. The Arc was discovered last year. https://en.wikipedia.org/wiki/The_Giant_Arc They said if the Giant...
2. ### MHB Formula to find arc radius using arc length, chord length, and/or segment angle

I'm attempting to write some code using the Ruby programming language that will give me the radius of an arc but the only pieces of information I have to work with are the arc length (L), the chord length (C), and the circular segment angle in degrees (A): I'm hoping someone can show me how to...
3. ### Find the electric field of a charged arc a distance R away

define charge at an infinitesimal length of arc $$dQ = \lambda R d \theta$$We only care about the x component of the electric field because the y components cancel due to symmetry $$dE_x = \frac{k_e dQ}{R^2} cos \theta$$ Integrate to add up the infinitesimal parts. A quarter circle means 90...
4. ### Engineering Finding arc length of a pipe between two tanks

I can't seem to find the arclength between A and B. I tried using L = integral (0.6 to 0.4) of sqrt (1+ (dz/dx)^2) to no avail. Would it be roughly similar to 400 km (the length from A to B) since the change in elevation could be considered negligible? Furthermore, how might I go about...
5. ### Help finding the Electric field at the center of charged arc

I am having trouble understand where area circled in red. I get that lamda is Q/L. The charge is +Q. Length is pi/R/2. I am having trouble understanding why the length is pi/R/2? Is it because the circumference of a circle is 2*pi*R and since we have broken this problem down to just...
6. ### Arc length of vector function - the integral seems impossible

The vector equation is ## v(x)=(e^x cos(2x), e^x sin(2x), e^x) ## I know the arc-length formula is ## S=\int_a^b \|v(x)\| \,dx ## I found the derivative from a previous question dealing with this same function, but the when I plug it into the arc-length function I get an integral that I've...
7. ### B ARC Centre reports HF Gravitational Wave Antenna

The full title of the publication is: Rare Events Detected with a Bulk Acoustic Wave High Frequency Gravitational Wave Antenna It is published in Physics Review Letters and reported in Phys Org. They have created a small piezo-electric device (< 2cm, though it gets bigger once you create an...
8. ### Calculating temp rise caused by electric arc in an enclosed space

Summary:: Given a known closed space/apparatus ( e.g. constant volume, pressure, density, current, temperature, voltage, spark gap distance - let me know if I missed something) how would I compute the change in gas temperature. Hello, Given a known closed space/apparatus ( e.g. constant...
9. ### Find the center of mass of an arc

In my mind, I had cut half of B and, thought it's semi-circle. Then, I was trying to find Center of Mass by taking it as semi-circle. But, I get an answer which is approximately, close to main answer. Someone else had solved it another way This way I can get the accurate answer. But, the...
10. ### Movement of a Ball Bearing within a cavity inside a Projectile

Summary:: Question concerning the behavior of a ball bearing inside a projectile fired straight up or at an arc. Within a projectile is a 1-inch cylindrical cavity, inside of which is a steel ball bearing that can freely roll along the length of the cavity. When the projectile is fired...
11. ### Finding Electric field E due to an arc

I need to account for tension, weight, and repulsion. For the tension, I can draw the x and y component of Tmax and see that the x components of the 2 tensions Tmax will cancel out, and there are 2 y components of the Tmax to factor in. Weight is just F = mg, where g is acceleration due to...
12. ### DC Inductor for an Arc Welder Conversion

Hello, I want to make a choke for a AC to DC welder conversion. The welder is a 50hz single phase oil cooled unit with constant current output upto 110A. I will bridge rectify the output to give rectified AC output. I need to smooth the output and as I need a constant current output, I'll...
13. ### Multivariable Arc Length Problem: Weird Form with Parameterization

Problem: See Attachment. Parts (a) & (b) are clear, but my confusion arises in (c)-- I feel like there is a much simpler form. While technically my answer is correct, there must be something I'm missing. I parameterized the curve C=(t, e^2t, e^2t) and got c'(t)=(1,2e^2t,2e^2t), which should...
14. ### The center of mass of a semicircular arc of non-negligible width

My attempt: 1) I am going to start this with a goal of setting up a reimann sum. First I divide the "arc"(?) of angle pi into n sub-arcs of equal angle Δθ 2) The total center of mass can be found if centers of mass of parts of the system are known. In each circular arc interval, I choose a...
15. E

### Finding the Centroid of an arc, and then of a sector, with heuristic arguments

The first part is not a problem, I let one radius lie along the ##x## axis and then we can write down ##S_x = \frac{M}{2}f(\frac{\alpha}{2})\cos{\frac{3\alpha}{2}} + \frac{M}{2}f(\frac{\alpha}{2})\cos{\frac{\alpha}{2}} = Mf(\alpha)\cos{\alpha}## from which we can then get the following after...
16. ### A Geodesics of the 2-sphere in terms of the arc length

I'm trying to evaluate the arc length between two points on a 2-sphere. The geodesic equation of a 2-sphere is: $$\cot(\theta)=\sqrt{\frac{1-K^2}{K^2}}\cdot \sin(\phi-\phi_{0})$$ According to this article:http://vixra.org/pdf/1404.0016v1.pdfthe arc length parameterization of the 2-sphere...
17. ### The Poulcen Arc: Exploring the First Electric Oscillator

Hi everyone 🙂 I have read this article about the arc converter, also known as the Poulcen arc. https://en.m.wikipedia.org/wiki/Arc_converter It was apparently one of the first electric oscillators. Apparently, an electric arc was produced between two electrodes to put in resonance a RLC...
18. ### Drawing Electric Arcs at 230 Volts

Hi everyone :) I open this discussion because I would like to know how electric arcs are able to be drawn. Indeed, I have been told that it is perfectly possible to draw electric arcs at very low voltage, by simply putting in contact two electrodes and then drawing them apart. I wanted to try...
19. ### How much steam is produced in an electric arc furnace?

Hello, everyone. Does anyone know how much steam is produced by an electric arc furnace in a set amount of time? I have not been able to find any information on this despite how much water is no doubt used to cool the electric arc furnace. Can anyone help?
20. ### I How to find the maximum arc length of this equation?

After seeing a discussion about graphs of the relationship ##x^x + y^y = r^r##, it got me interested in attempting to see what the graphical appearance of ##{^{\infty}x}+{^{\infty}y}={^{\infty}r}## would look like. The first step I did was use the relationship of...
21. ### Helicoidal movement: acceleration vector, arc length, radius of curvature

I have tried to solve it and I would like a confirmation, correction or if something else is suggested... :) Helicoidal movement
22. ### MHB Find the Angle of Parable Tangent from Human Running Step

I am a masters student studying motion analysis in human running. I need to find the angle of the parable tangent derived from the theoretical arc traced by a foot during a step and the ground (see attached). The arc comprises of a persons step height and step length and I need to find the...
23. ### B Arc formula without the use of radius and angle

I had created a formula on arc of a circle...How can I publish it ..So that people see it and decide is it important or not.
24. ### I Arc diameter as a function of arc length and chord length

I'm trying to determine if a certain bicycle tire size will fit my bike, and that determination is based on the inflated diameter (or width) of the tire. As such, I'm trying to come up with a formula that will give me the diameter of a bicycle tire as a function of the tire's carcass width and...
25. ### Determining the final velocity and acceleration magnitude traveling along an arc

Problem Statement: The motorcycle is traveling at 40 m/s when it is at A. If the speed is then decreased at v'=-(0.05s)m/s^2, where s is in meters measured from A, determine its speed and acceleration when it reaches B. I attached a picture of the problem. Relevant Equations: S = S_0 + v_0(t)...
26. ### MHB Finding Chord length given arc length and arc height?

I am in the process of making a tent and need to get two curved surfaces to meet. I need to find the length of a Chord of a circle given that I have the Arc length and Arc Height (that's all), no radius or anything else. I suspect that I will need a radius to find this. Or am I missing a...
27. ### Trapezoidal rule to estimate arc length error

I got the first part of it down, $$L=\int_1^5 \sqrt{1+(\frac{1}{x^2})}dx$$ I just want to know if it's right to make your ##f(x)=\sqrt{1+\frac{1}{x^2}}## then compute it's second derivative and find it's max value, for the trapezoidal error formula.
28. ### Bending a beam from straight to an arc with axial force

Hi, If I have a straight beam and I start to push its ends towards each other with force F, the beam will obviously bend into an arc. What is the height/amplitude at the center of the arc when the beam length is l and the beam ends have been displaced by d. How much force (P) the center part...
29. ### Electric arc: How to calculate the required voltage for a light bow?

<Moderator's note: Moved from a homework forum.> Calculate the required voltage to produce a electric arc between 2 iron nails (distance: 3cm). I´ve read in the internet that you need 1 kV per mm. But how can I calculate this value, that I need 1kV per 1mm?
30. ### MHB Find radius, circumference, area and arc length in circle

So I've been able to solve A.12 inch B.24 inch C.75.3982 D.452.389 Cant solve e. Arc length can anyone please explain the formula. Thank you
31. ### I Looking for intuition on differentials and arc length

Please see the attached image. It's a part of a study guide for my final, but I didn't put it in the homework section because I already got the answer, I just don't know what it means. The question has to do with the differential of an arc length. I made some drawings to see if I could make some...
32. ### Projectile motion problem, given the KE at the top of the parabolic arc

Homework Statement Calculate the angle of Projection for which Kinetic Energy at the highest point of trajectory equal to one-fourth of its kinetic energy at point of projection? Homework Equations Range and height of Projectile equations The Attempt at a Solution [/B] I've made two...
33. ### Magnetic field due to a straight wire and circular arc

Homework Statement Find the magnitude of the magnetic induction B of a magnetic field generated by a system of thin conductors along which a current i is flowing at a point A(O,R,O), that is the center of a circular conductor of radius R. The ring is in the yz plane. Homework Equations [/B]...
34. ### I Arc length constant, despite varying the period via varying amplitude

This is not a school problem, just my own mucking about, but since it has the form of a problem, I am willing to shift it to the "homework problems" rubric. If there is a theoretical string (no thickness, etc.) that is non-stretchable tied to two endpoints and is long enough to be able to form a...
35. ### MHB Secant and Tangent Angles in Circles, finding an arc length.

I got 138.17, but that isn't correct. I don't know how to do it, since the only way I thought, gave me the wrong answer. Can anyone help?
36. ### Using dy/dx to find arc length of a parametric equation

Homework Statement I have attached a picture of the problem in the attachments I need help on the last section, (part d) Homework Equations (1)##∫√( (dx/dt)^2+(dy/dt)^2)dt## (2)##∫√( 1+(dy/dx)^2)dx##[/B] The Attempt at a Solution In order to get the answer we just need to find the...
37. ### Monitor restarts when I make an electric arc

Why does my laptop's screen refresh every time I bring a metal object (any size) to my electric lighter? -Happens when I am 1 foot away from the laptop -1 foot away from the external monitor's wires (HDMI & power) 1. Video footage (MUST WATCH) NOTE: the laptop screen also flickers a bit NOTE...

39. ### Calculating Arc Length and Area of Cylinder Side

Homework Statement Let r be a positive constant. [/B] Consider the cylinder x2 + y2 ≤ r2, and let C be the part of the cylinder that satisfies 0 ≤ z ≤ y. (3) Let a be the length of the arc along the base circle of C from the point (r, 0, 0) to the point (r cos θ, r sin θ, 0) (0 ≤ θ ≤ π). Let...
40. ### Should I use the arc tan of (ay/ax) or of (Fy/Fx) and why?

given: 128kg F1 = 28 N, F2 = 57 N, F3 = 38 N, θ1 = 30°, and θ3 = 60°.They are asking for the angle (measured relative to the positive direction of the x axis in the range of (-180°, 180°]) of the asteroid's acceleration? The problem is displayed on quadrant I and IV for vector notation I got...
41. ### MHB Find s, the arc length of a circle

The question is asking me to find s, the arc length of a circle. How do I convert my answer in radians to the book's answer 7.54 meters? Theta = 4pi/5 radius = 3 meters See picture.
42. ### Gearing Backlash Arcsine to Arc minutes

Working on a project at work for backlash in a gearbox. I need to know the amount of backlash in arc minutes that this particular ratio has. Wondering if my approach is on the right path. So can calculate the loose tolerance by the amount of end play in the input shaft and output shaft, add...
43. ### How to convert an inch dimension to arc minutes for precise measurement?

How can l convert an inch dimension to arc minutes? We have a customer who requires a 3 foot diameter roll not move more than an 1/8 inch. I need to convert the 1/8 inch to arc minutes to compare to the backlash in our gearing. Any help is greatly appreciated.
44. ### B Difference Quotient vs ARC of a Function

These are the two things that I'm going over in my PreCalculus class- the Difference Quotient and the Average Rate of Change of a Function. I'm confused as to what exactly they are, and how they relate to each other. Average Rate of Change= ##\frac {f \left(b\right) - f\left(a\right)} {b - a...
45. ### Arc Length of Parabola & Square Root Function

Homework Statement Consider the curves: y = x^2 from 1/2 to 2 and y = \sqrt{x} from 1/4 to 4. a. Explain why the lengths should be equal. b. Set up integrals (with respect to x) that give the arc lengths of the curve segments. Use a substitution to show that one integral can be...
46. ### Electric field in the center of an arc

Homework Statement Consider a conductor wire with a charge Q uniformly distributed, shaped in the form of an arc of radius R and amplitude 2A (were A is a given number between 0 and π). Find the value of the electric field in the center of the arc. Homework Equations ##E(P)= \int K_e...
47. ### Help me find the arc length of a parametric equation....

1. The problem statement, all variables and given/k nown data x = (sin(t))^2 y = (cos(t))^2 t goes from 0 to 3 pi Homework Equations ∫ \sqrt{ {(dx/dt)}^2 + {(dy/dt)}^2 } dt The Attempt at a Solution ∫ \sqrt{ {(2sin(t)cost)}^2 + {(-2cos(t)sin(t))}^2 } dt ∫ \sqrt{ 4(sin(t)cos(t))^2 +...
48. ### Plasma arc with multiple electrodes

is it possible to create a plasma arc across multiple electrodes? like: cathode___ anode____________________cathode then back to anode from source? is this possible? and if yes does it need electrolyte at the anode in the middle and how to apply it?
49. ### I Arc Length Parameterization for Unit Circle: Cos(s) & Sin(s)

(cos(s), sin(s)) gives an arc-length parameterization of the unit circle so that the speed is constantly 1, but the second derivative doesn't give zero acceleration which should be the case with constant speed?
50. ### MHB Using Angles on the Same Arc Theorem

im trying to use angles on the same arc theorem