Hi.
If a plate capacitor is charged with some charge ##Q##, then there's a voltage ##U=Q/C## between the plates. The electric field between the plates is ##E=U/d##.
Voltage is path independent, if I connect the plates with a cable of length ##l\gg d## the voltage across the cable is the same...
I normally use ELEK Cable Pro to calculate my cable sizes and it works very well however I have a project at the moment which has a circuit which I need help calculating the correct size cable for;The circuit is for an 18.5kw 400v motor. I have used the following
Load – 18.5kw
V- 400v...
I have an application where I'm trying to lift an object by using a pulley and pulling on the cable. We were forced to use a pretty small pulley and thin cable, so my question is how to analyze the total stress of the cable? I should be looking for axial stress, bending stress (cable around...
A steel cable 3.00 cm 2 in cross-sectional area has a mass of
2.40 kg per meter of length. If 500 m of the cable is hung
over a vertical cliff, how much does the cable stretch under
its own weight? Take Y steel ϭ 2.00 ϫ 10 11 N/m 2 .Y=([L][/o]F)/(A*delta_L)
My attempt of solution...
Hi all,
I was not sure where to post this, so feel free to move the thread if the forum is not the most appropriate.
I was reading about safety in fiber optics and the fact that one should not be staring into a fiber optic cable to avoid eye damage. That's pretty obvious, but it also raises a...
I am newbie in the area of clutches. I am making a motorized cable reel (DC motor) which I needed to make it easy for anyone to pull the cable reel out manually without much effort. Only pulling the cable out is manual. The retraction of the cord is done automatically via the DC motor. So, based...
Hello all
Apologies if this is in the wrong section.
The below tv show about an air crash investigation makes a statement about forces on a cable that did not ring true to me. I wanted to check my understanding of forces.
Simplified as I understood it the following seemed to be suggested...
A large number (56) of 18 gauge-ish connection pins are presented by the connector. They are wired together in large groups on the "client" side of the connector (4 electrodes). We wish to re wire these groups together and then split them off into 24x 18 AWG a few feet removed from the...
Homework Statement
your car is stuck in the mud and you can’t pull hard enough to get it out. You do, however, have a long cable that you connect taut between your front bumper and the trunk of a stout tree. You now pull sideways on the cable at its midpoint, exerting a force f. Each half of...
Homework Statement
Given the nature of the title of the problem, I need hints to guide me in the right direction. I am sort of lost.
A student has a large quantity of a flexible cable. If she cuts a piece of that cable and hangs it vertically, the longest piece that does not break under its own...
Homework Statement
I have attached the problem
Homework Equations
E*A = Qenc/ E0
The Attempt at a Solution
At the moment I am looking at the problem more conceptually and seeing what is happening at each point and I wanted to know If I was on the right track.
r<a
As all charge would...
Let's say we have a coaxial cable with a 2d rectangular surface lying between the inner and outer conductors and running the length of the cable. I'm trying to understand why the magnetic flux through this surface only includes the magnetic field generated by the current flowing through the...
Does such a thing exist. I have a device that only has a slot to write data to a micro sd card. I have an external USB hard drive. Is it possible to hook up my external hard drive to the micro sd slot in my device? Like a male USB cable into the external hard drive that has a male micro sd...
Prior to my life as a database administrator I was a hi lead logger in coastal British Columbia, which involves harvesting logs with machines capable of putting huge strain on cable and hydraulic systems. What got me to thinking this was a friend just let me know someone we know was recently...
What is electric field distribution around two conductor cable connected to DC power supply? Assume power supply is isolated and not grounded. Assume cable is straight.
Case 1: no current runs through the cable. One wire is positive, another – negative. Negative or zero? If we think in terms of...
Homework Statement
A 50.0 kg 6.00m awning is held up by a wire in the middle. A 15kg sign hangs at the end. Calculate the tension in the massless wire and the magnitude of the net force from the wall acting on the awning.
The cable forms a 40 degree angle with the awning at the bottom right...
Homework Statement
"An elevator cab and its load have a combined mass of 1600 kg. Find the tension in the supporting cable when the cab, originally moving downward at 12 m/s, is brought to rest with constant acceleration in a distance of 42 m."
##m = 1600 kg##
##v = 12 m/s##
##d = 42 m##...
Every physics books show that wave prograpation in coxial cable is TEM wave, like in the picture. But we know that J=σ E from ohms law, which says current in same direction with E field, which is not the case here. What do you think the reason is ?
Homework Statement
A 400kV line is carrying 1GW of power and experiences a line resistance of 5 ohms. What is the power loss in the cable due to resistive losses?
Homework EquationsThe Attempt at a Solution
You are given 4 potential answers to this question
a) 3.2x10^7 W
b) 78 W
c) 5000 W
d)...
Homework Statement
Mass of elevator = 500kg
Counterweight = 134kg
Force in cable C1 is 1.2kn
Determine the acceleration of the elevator and the force in cable C2
Homework EquationsThe Attempt at a Solution
a = f / m
a = (C2 - C1) / m2
a = ((m2 * g) - C1) / m2
a = ((134 * 9.81) - 1200) /...
A small factory has decided to go Carbon neutral and has installed its own wind turbine. The wind turbine is installed on land belonging to the factory 1 km away. The factory owner needs 2km of copper wire of diameter 3mm to connect the turbine to the factory. The resistance of the cable is 1.2...
These things are pretty amazing. Very cheap, they are a 3 port device which basically works like a diode, but for AC. For example, it let's a signal pass from coaxial connector A to coaxial connector B but not B to A. There is also a third coaxial port C which passes C to B but not C>A or B>C...
Homework Statement
A platform (m = 5,0kg) is suspended from 4 steel cables whose length is 3,0m and diameter 2mm.
a) How much further will the platform sink if a mass of 50kg is placed on the platform?
b) What is the maximum load that the wires can hold before breaking?
Homework Equations...
Hello.
I'm using coaxial cable to transfer power to the load with original aim that radiation from the coax would be low or almost nothing as current on both conductor (central conductor and outer shield layer - ground) are equal in amplitude and opposite in phase so their sum is zero; zero...
Homework Statement
A coaxial cable consists of two concentric cylindrical conductors as shown here: http://puu.sh/luFZx/7f3e1ccb07.png . The inner cylinder has a linear charge density of +λ1, meaning that each meter of the cable will have λ C of charge on the inner cylinder. The outer cylinder...
Homework Statement
An 11 kg traffic light hangs fro ma structure as shown.
The aluminium pole AB is 7.5 m long, and weighs 8 kg. Determine the tension in cord CD
Homework Equations
T = rf[/B]The Attempt at a Solution
Ignore the AC height of 3.8 m, and replace it with an AD length of 7.5...
We have a coaxial cable with inner radius a and outer radius b. The coaxial cable is modeled as two very long circular metal cylinders. I'm supposed to calculate the electric field E, the electric potential V and the charge enclosed Q when a voltage is applied between the metal cylinder...
in my country colours of cable core are
a)Single core RED
b)Three Core RED-YELLOW-BLUE
c)Four Core RED-YELLOW-BLUE-BLACK
d)Five Core RED-YELLOW-BLUE-BLACK-GREEN.
but can anyone tell me according to HD 308 S2 and IEC 60304 standard what should be the core colours of low frequency cables. ?
This just out of curiosity because the system works either way, I just wonder why.
I have a high precision GPS system, there are two antennas placed about 2 meters apart with cables that are about 8 meters long going back to an embedded computer. Besides giving you the position, it uses the...
Hello, I would like to calculate the current distribution in a coaxial cable where the skin effect is significant. I asked this question on stackexchange and I provided pictures and more details there...
1. Homework Statement
In one of the versions of the "Giant Swing", the seat is connected to two cables, one of which is horizontal (Figure 1) . The seat swings in a horizontal circle at a rate of 33.0 rev/min .
If the seat weighs 295 N and a 869-N person is sitting in it, find the tension in...
Hello. I have DC going through a coaxial cable, and I have calculated the E fields of the two dielectrics in between to be E_1 and E_2 with help of their D-vectors. The dielectrics are cylindrically shaped like the conductors. As in, one is in contact with the inner conductor, and one is in...
Homework Statement
A turtle is crawling along a cable made of super elastic material. The turtle speed is constant at 1mm per second. The cable's length is 1km and at the same time it is being stretched at a constant speed of 1km per second. Suppose the turtle is immortal and the cable can be...
The standard characteristic cable impedance for the microwave industry is 50 Ω. Why is 75 Ω the standard for cable TV? Making a 75 Ω low loss cable with a 3 GHz rating pushes the limits of technology. Typically a 50 Ω cable would be less than half the diameter, lighter, more flexible and...
Homework Statement
Homework Equations
F=ma
The Attempt at a Solution
Does the total Force F=50N divide evenly between m1+m2 and m3? Meaning the tension between m1/m2 & m3 is 25N given m1+m2=m3. Also, is the acceleration between m1/m2 & m3 the same as the acceleration at m3...
Homework Statement
A) Draw a free body
B) determine the tension in rope A and the reactions in B.
Homework Equations [/B]
Standard equilibrium equations
The Attempt at a Solution
My free body shows a collinear force T through the rope, the given downward force at 5ft, and then a Bx and By...
Homework Statement
Consider a shorted coaxial line with a resistive inner conductor with radius a, and a perfect outer conductor located at radius b. A DC voltage is applied at the input end. Find the electric and magnetic fields in the dielectric region (a<r<b), assuming the battery sets up a...
Homework Statement
Looking for the tension in cable Tcd when the moment on A is equal to 0.
P1 = 73N.
I’ve had several attempts but I can’t seem to obtain the answer, which is 110,8 N.
Can anyone help me with this question?
Homework EquationsThe Attempt at a Solution
I can get some old massive size power transmission cable straight out of the power station. I have the space to erect some posts and go just over 500m but with permission I might get 1km or more.
Will use a metal pipe in the ground for ground.
This is not technically a dipole, would a dipole...
Hello Forum,
A coaxial cable is a two conductor transmission line.
If we connect a DC voltage source via a coaxial cable to a resistor so that the positive terminal is connected to the inner conductor and the negative terminal to the shield , the current will flow through the whole...
Hi guys
I received electrical drawings for a construction project as a part of invitation for tendering.
The project includes a number of SMDBs connected to two MDBs which are connected to two transformers. Looking at the schematic design, I found that a SMDB is connected to one of the two...
Homework Statement
Coaxial cable has double layered dielectric.
a=2mm, b=4mm, c=8mm, εr1=3, εr2=4.5, Uab=1000V
1. Calculate capacitance per unit length of a cable.
2. Calculate inner and outer charge densities of a cable.
2. Homework Equations
Gauss law
C'=Q'/U
σ = nD
σp = nP
3. The Attempt...
1. Homework Statement
The tension in the cable is 800LBs. Find the depth of water that produces this tension. The gate is hinged at B; the cable is attached at A. (Figure 1)Homework EquationsThe Attempt at a Solution
OK, so this is just 2 opposing lever arms: the tension in the cable is...
Hi,
I'm new to PF so this is my first post. I have a real case scenario as my first thread in which I have a gravitational tensioning system that provides tension to a cable conveyor. The tensioning system includes a series of pulleys in a particular reeving arrangement that is fixed on one...
Hi guys !
Is there any way to detect current /generated magnetic field using hall effect sensor ss49 ?? or any other to just detect current in that cable ? please help me .
Hello there,
All Electrical Engineer fellas, :smile:
Someday ago, I had been assigned to conduct a building audit of one company in Indonesia. For completing this task, I need all international standard about electrical equipment installation, especially for wiring / cable.
Is there anyone...
Hey
My question relates to piezo cable under saddle pickup for accoustic guitars. They change the guitar's sound into electrical energy. They work almost like a microphone.
But these cables are bendable, would that mean bending them can cause an electrical impulse along Becasue they are up of...
If even feasible, what minimum type/size cable reqd with trolly attached that would have maximum 1000 lb load suspended from it, that would be pulled up, from atop, by second separate free line for the following location; 1,000 foot elevation change to where base anchor point was, horizontally...