Hi
If the length of parallel medium-voltage cable runs is approximately 20 meters, and cable sheath is grounded only at one end, does it matter how the parallel phases are installed on the cable rack? If the straightforward installation method doesn't follow the rule for arranging the phases on...
Are there motherboards for desktop computers that can transmit audio over DVI or HDMI cables to a TV when the TV is used as the computer's display? If so, what terminology is used in the specifications for such a motherboard to indicate this capability?
For example, the manual for a Samsung TV...
Hi Everyone! I have a photonics problem that I was wondering if anyone may be able to shed some light on (no pun intended).
I work for a company that is designing a fiber optic emitter/detector as a part of one of our products and we've noticed something that would appear to defy physics...
Summary:: Markov processes (A weight of L tons is suspended by n cables which share the load equally)
A weight of L tons is suspended by n cables which share the load equally. If k, for 1 ≤ k ≤ n − 1, of the cables have broken, then the remaining (n − k) cables share the load equally. As soon...
Hello,
Recently while familiarizing myself with the rodent menace affecting Fiber optic networks, I came across this rather novel use for the dark, or unused fibers in buried cables. The method apparently holds a lot of promise as well as significant advantages over many current Seismology...
Before, sorry for my English, it is not my native language
I already have the solution to the issue, I just didn't understand a step.
1) Calculation of weight force (vertical):
$$ F_v = \frac{\rho \pi R^2 . L .g}{4}$$
2) Calculation of force due to water pressure on the plate (horizontal)...
Hello guys!
I am a student who currently works on a project based on electrical detection and voltage measurement in electrical cables remotly. So in order to accomplish my work, I'm seeki ng for new ways to detect voltage. I already have some ideas such as using magnetic fields or measuring...
Problem illustration:
The possible answers are:
I don't understand why it says Mc if it is asking for the moment at A, not C. But maybe I am getting something wrong.
So with the formulas I posted above, I have this:
Hi
I have not been keeping up with the latest USB standard, is the latest one USBIII? What is the speed of this?
Also, I want to run a USB cable at least 4m long, do they have USB cable that long and still work for the fastest USB standard?
I know in the past, even for USBII, there is a...
I recently bought a KiwiSDR and it's my first SDR so far. I was wondering, what antennas you guys recommendation for it and whether this recommended antenna is truly good for it (it was listed on the KiwiSDR site as a recommended antenna, but it's a bit pricey for me). I'm trying to find signals...
Hello, I've got two computers that are in separate rooms and I have placed plastic conduit through the small space above the ceiling. Which will have a USB data cable, an Ethernet network cable, and a HDMI cable inside. The conduit length is about 8m long. And I was wondering if this setup could...
A 30 kg sphere is held stationary by two cables. One cable is attached at 60° above horizontal. The second cable is horizontal and attached at the side of the sphere. Find the tension in both cables.
Newton's 2nd law: F=ma, which means a = (∑F/m)
We can also find the weight: W = mg
Let's say...
Imagine a steel I-girder lifted by a single wire rope. If the rope is not perfectly centered along the girder length, the girder will rotate about a horizontal latitudinal axis through its centroid.
Imagine a girder pair lifted by two wire ropes, with one rope on each side of the girder...
Hi PF
Is it possible to perform accelerated lifetime test of thermal ageing on power cables?
Let's assume that the cable manufacturer guarantees a service life time of 20 years at max operation temperature 90 [degC]. Is it possible to estimate the expected life time of a cable if I choose to...
Homework Statement
Homework Equations
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apparently noneThe Attempt at a Solution
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Hi, this is a question from the OCR for self studying purposes. Only the first question is relevant for me. I know that the solution is 120N in the opposite direction to the weight, but i can't get to...
Homework Statement
Why are cables thin when used as ties? Why are they not equally as thick as say struts?
Homework EquationsThe Attempt at a Solution
Is it because when in tension the tie cannot buckle? or because when in tension it cannot shear?
Steel has the same compressive strength as...
Hello Everyone,
I was learning about prestressed concrete and how it works. Concrete is very strong under compression but weak under tension. In the case of prestressed concrete, the steel bars are pulled and become elongated.
How much do the steel bars elongate when they are pulled?
The...
Homework Statement
Problem 5 here:
http://www.princeton.edu/~romalis/PHYS203/HW1.pdf
Homework Equations
N/A
The Attempt at a Solution
The part that really confuses me is where it says that the cable lengths are adjusted so there is no shear stress on the bridge. What exactly does this mean...
Hi,
I have 6 cables. Each cable has 3 wires: zero, phase, earth.
Each cable supplies 320W 230VAC heater (I have 6 heaters).
I am looking for 1 multi pin connector for all these cables for quick plug in/out.
Link to example connectors...
Temperature with hot spot by Ir thermal cameras of modern development is being used
for measuring on the object of terminal surfaces and cable working temperatures in
particular working loads. However, so far no measurements has been designed to
obtain the result on the flow of current...
Homework Statement
https://ibb.co/g6iKDQ
Calculate the magnitude of the force on cables 1 and 2 in the figure below if θ_1 = 55° and θ_2 = 35°.
(Round your answers to two decimal places.)
Homework Equations
Is my method incorrect or did I go wrong somewhere in my calculations??
The...
To calculate the displacement current in a coaxial cable (with equal and opposite currents on the inner and outer conductors), most standard texts use the magnetoquasistatic approximation, which ignores the time-varying electric field term in Ampere’s Law.
Using this approximation, the...
When attempting to find an answer to the "quality" of sound one attains from various audio cables, most of the research leads to the very subjective answers of audio/sound engineers. I was hoping to gain some insight from a physics/engineering perspective.
I'm curious if an expensive or...
Homework Statement
Picture a seat that is supported by two cables. One is horizontal, and the other makes an angle of 40 degrees to the vertical. The swing swings in a horizontal circle at a rate of 32 rev/min. The horizontal cable is 7.5 m long. The person sitting on the seat at the end of the...
Hi,
I'm in a bind trying to determine how to handle impedance matching through a joint of copper wire sandwiched between two 50-ohm coaxial cables (the joint is an interface between atmosphere and a UHV system). There is a signal pulse with a rise time of 2 ns coming through one of the coaxial...
If I have a light bulb that take energy by the normal current of the house but I want connect at the bulb an other part of energy from an other source of electricity but with an inferior Voltage.
This circuit will work or no.
How to connect the second source of energy to reduce the amount of...
Hello,
Why do self regulating heating cables have such low power output per foot?
Power output in these cables does not exceed 20 W/ft at 10 degree C, and decreases as the temperature goes up.
Many of the cables I saw can withstand high temperatures (250 degree C power off and 150 degree C...
Homework Statement
http://postimg.org/image/vzhqi8er5/
Homework EquationsThe Attempt at a Solution
I understand all the calculations here - http://www.physicspages.com/2012/10/18/coaxial-cable-with-dielectric/
I have one issue that is bugging me though - if λ charge density is distributed over...
Homework Statement
A weight W is supported by bar AO and cables AB, AC, and AD. Point A lies in the xy plane, if the bar and cables have the strengths listed below, determine the largest value W may have.
Hint given: A FBD of joint A is recommendedto being this problem. Bar AO should be...
Homework Statement
Homework Equations
I know that yin = 0.7mm, y2 = 0mm, the index of refraction for the sphere is 1.8 and the indices of refraction for the air surrounding it is 1.
The Attempt at a Solution
Not sure how to even begin with the given information. I was thinking I could...
Hello
Why does Mineral Insulated heating cables have such limited power output per feet and maximum operating voltages?
I thought it has to do with the dielectric strength of the MgO, that is used as an insulation in the coaxial cable, but the dielectric strength for MgO is higher than the...
How are power distribution cables parallel-ed to split loads optimally? If the cables were exactly identical this would be easy but how is it achieved in general?
e.g. Say there's a 11 kV to 420 V distribution transformer but the primary load is some distance away. Assume the load increases...
What's up people? I'm new in this wonderful forum. I have several questions about circuits, and they are not really common, I mean, I find them somehow complicated, but I would really come to enlightenment if you guys gave me some clues.
1.- So, let's suppose we got the simplest circuit, a...
Homework Statement
There is a girder hanging from a crane by two cables. The girder is 2.6m long and hanging at an angle. The weight of the girder is 0.50 kN. Calculate the tensions of each cable.
Homework EquationsThe Attempt at a Solution
I would divide the two cables into their x and y...
Homework Statement
Homework EquationsThe Attempt at a Solution
1. I first found the angles each cable made with the pillar.
2. With these angles I found the components of the forces in the x and y direction.
3. So ∑Fx and ∑Fy were found.
4. Then using these values I equated...
I was browsing amazon for some basic HDMI cables and was flabbergasted when I came across some by AudioQuest Diamond. They cost $1,494.75 for 6.5FT.
https://www.amazon.com/dp/B003CT2A2M/?tag=pfamazon01-20
The information gives
Solid Perfect-Surface Silver (PSS) Conductors
Low Jitter, Low...
Hello all. I am not an electrical expert here, just know enough to wire basic things at home (i.e. switches, outlets, etc)...so please be kind.
My situation is this. We recently bought a new house and have found a couple of mysteries. The biggest one is that there are several electrical...
Homework Statement
A heavy box weighing 25kN is to be lifted by 2 overhead cranes with cables inclined at 40° and 30° with the vertical respectively.
i) Find tension in each cable during lifting.
ii) Due to safety concerns, the tension T2 in second cable is to be minimized. Find the angle...
Homework Statement
A 30Kg neon sign is suspended by two cables, as shown. Three neighbourhood cats (5.0 Kg each) find the sign a comfortable place. Calculate the tension in each cable with the cats are in the positions shown.
Homework Equations
xCM = m1x1 + m2x2 ...
Hello guys,
I have to make a short circuit calculation for school but I am a bit lost.. I have a copy off the IEC61363 and internet connection as my help lines.
Homework Statement
The network consists of a generator feeding to switchboard A with a cable in between, on the same...
Hey guys,
I'm looking for examples of real life systems which uses a board with holes to redirect cables in tension (as opposed to pulleys) for some inspiration on a project I'm working on.
I've attached an schematic of what I mean. I've tried searching google for systems but it's a hard...
Homework Statement
Explain the physical principle of total internal reflection used by optical cables. Calculate the critical angle of incidence that corresponds to a refracted angle θair = 90
Next, calculate the critical angle for a bare glass fiber submerged in water nH2O = 1.33...
Homework Statement
We need to connect two coax cables with the same dielectric (εr = 9) but
with different dimensions as shown. How big must be the radius of the
outer conductor of the second line in order to match two lines?
How would the velocity of the wave propagation change, if we...
Homework Statement
A 1000N beam is loaded with a 2000N filing cabinet and supported by two cables. If the beam is 8 meters long and the filing cabinet is 2 meters from the left cable, what is the tension force in each cable?
Homework Equations
T= F /d
The Attempt at a Solution
For...
Hey.
If i Have a 3x400VAC system, and I want to calculate the voltage drop over the cable "vectorially" - or what you call it :) - how do I do this?
U.nominal=400V
I have tried this method:
\DeltaU.conductor=I.1*Z.cable1+I.2*Z.cable2+etc. and then I will have to find the new voltage ->...