Source Definition and 1000 Threads

Summary:: I have a fibre coupled LED light and an achromatic doublet lens, I know by placing the collimating lens at a distance equal to the focal length of the lens, the light will get collimated. But is the a simulation software available where I can input the parameters I can so as to...

I did a kvl loop and got V + 5Io - 15 Io = 0 So, V = 10Io Then, substituted dq/dt for Io and q/c for V I get to dq/dt - 50000q = 0 solving this equation i get q = C x e^50000q (c for constant) my Io = dq/dt so Io now is 50,000Ce^50000q now my Q(0) is 3 x 10^-5 So my Io (0) should be...

Almost all (compiled or interpreted) programming langues store the program source in the form of a series of bytes (using an encoding like ASCII or UTF-8) into a text file, enforcing the grammer of the programming language using a parser (as part of the compilation process or interpretation of...

I am not sure if I should use the word 'current' or 'charge' but my question is whether, in a typical U.S. residential 120/240 split phase system, is the local transformer always the source to which current (charge?) must return? Or can it bypass and go direct to other PoCo elements/generators...

https://phys.org/news/2021-11-ultraluminous-x-ray-source-galaxy-ngc.html Spectral and Temporal Properties of Ultra-luminous X-ray Source NGC 55 ULX1 https://arxiv.org/abs/2111.06637 Same paper - https://academic.oup.com/mnras/advance-article-abstract/doi/10.1093/mnras/stab3307/6428406 From...

As per ohms law the current is generated based on voltage and resistance V=IR. So if 5v and 1k resistor the current 5mA flows in resistor. But if I take a current source, can I pump any amount of current to resistor? So, current drawn is not characteristic of resistor?

Okay so This is what I've tried; a) A formula I've found in the lecture notes; $$ U_a = U_q - R_i*I $$ To get I used the ## I = \frac{P}{U} ## formula I get I to be 0,46 A.Now put back in formula for and rearange to get Ri should be $$ \frac{Ua-Uq}{I} = Ri $$ and the solution should be 0,43...

I am new in Vgate software. I've tried a lot of things, but nothing works. I need to create a conical source that is 4 cm in radius and 16 cm in length. Example in photo attached

If I have a source of radioactivity that is concentrated instead of evenly spread out, like a "tablet" source instead of a evenly distributed aerosol/dust on ground for example then is it possible to even estimate the total number of disintegrations (Becquerels per second) by measuring the...

I have checked several textbooks about the heat equation in a rectangle and I have found none that deals with my exact problem. I have though to use separation of variables first (to no avail), then Green's function (to no avail), then simplifying the problem for example by defining a new...

Floating inside a closed spaceship, no windows, not knowing if I'm free falling near a gravity source or far away from any gravity source, are there any experiments that can be made, to determine if there is a gravity source near and if there is such an experiment, to determine the gravity...

Hi! I'm playing around with a type of electron (and by electron/molecule interactions: ion) source that was briefly touched upon in the 1960's. The basic idea is to use a channel electron multiplier "channeltron" with the anode removed; similar to a single MCP channel. The burst of electrons...

Summary:: I am trying to find some good folks with knowledge in FOGA coding for some ADC boards our EEs are spinning out, but am having terrible luck so far... I am trying to find some good folks with knowledge in FPGA coding for some ADC boards our EEs are spinning out for pulse heigh...

A carousel has the shape of a circular disc with radius 1.80 m and a mass of 300 kg. There are two people with masses of 30 and 45 kg out on the edge while carousel rotates with the angular speed 0.6 rad / s. The people move towards the center of the carousel Calculations show that the...

I am still so totally confused about the ultimate source of the photons of the CMB. I am getting really confused by online sources, who are either not very clear, or seem to contradict each other. I feel like I have narrowed it down to two sources; 1. The early universe was full of high...

I would like to solve a coupled system of two PDEs using Comsol for the following geometry: Equation 1 (valid for 0⩽Z⩽bm): The initial and boundary conditions are: Tm(r,t→0)=20 Tm(r→rw,t)=70 Tm(r→∞,t)=20 However, for bm⩽Z⩽bm+b2, the equation to solve is: With the following initial and...

Can electromagnetic radiations exist on their own without any source (i.e light existing on its own without flashlight). If light can't exist on its own so sources are necessary for light or any EM radiations in order to exist, how about the EM fields?

I am hoping this forum may be a good page for this question. Not sure where else to post. I have been asked if I can write a user GUI to control a system that we build--the system is made with the fairly common electronics board designs and PIC MPs and presently is controlled from a...

Given values : - Distance between the slit source and the screen L - d1,d2 The problem is to detemine the color of the two lights

We are tasked to solve for the steady state voltage v using superposition theorem. I start with solving with voltage source using mesh analysis and got the current flowing through the 3 ohms resistor and get the first value of the voltage which is 3.2cos(6t+126.87). Now my problem is I am...

Mass curves the spacetime. In electrodynamics, an electron curves an electric field (if there is one) - because it has an electric field of its own. The electron is the source of an electric field(maxwell equations) Is there an analogy to space-time, is mass the source of the space-time field as...

Hi all I am trying to calculate Source Level 'SL' of a underwater acoustic Cylindrical Array with multiple Transducers. The array has 03 Rings with 32 transducers in each Ring. The spacing between each ring is around 0.18m whereas Dia of each Ring is about 1m. Each transducer is being driven...

I am currently performing some experiments to calculate the distance between a light source and a lux meter where the light source points directly towards the lux meter. Is it possible to calculate the exact distance between the light source and the lux meter given that we have a lux value...

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considering that a simple mirror may reflect 99.9% of the visible light

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I am reading Griffith's textbook on EM. There is a problem asking to find the force acting on the northern hemisphere by the southern hemisphere of a uniformly charged sphere. The solution idea is to find the expression of the E field by Gauss's law and integrate the force over the northern...

Check this link: How to override the copy/deep-copy operations for a Python object? Can anyone explain, in layman's terms, what is going on in this source code? from copy import copy, deepcopy class MyClass(object): def __init__(self): print('init') self.v = 10...

How can we evaluate the linearity of a dependent voltage/current source? Components like resistors are easy to deal with because they always obey a linear equation. Dependent sources are more complicated because their voltage/current relationships depends on other parameters within the circuit.

We need to derive the Maxwell "with source" equation, of course, using the tensor equation $$\partial F^{\mu v}/ \partial x^{v} = j^{\mu}/c$$ D is the spacetime dimension To do this, it was said to us vary the action wrt the ##A^{\mu}## The first term just vanish, and I want to evaluate the...

Hello, this is my working. My professor did not give any answer key, and thus can I check if I approach the question correctly, and also check if my answer is correct at the same time. for t < 0, V(0-) = V(0+) = 60V I(0) = 60 / 50 = 1.2A When t > 0, $$α = \frac{R}{2L}$$ $$α =...

Is there a specific particle or force that gives an object inertia? Going back to the 1940's science fiction ideas of "inertialessness", is there a way to nullify or remove an objects inertia? And if so, could an inertialess object go faster than light?

Dear PF, I am trying to solve practice problem 8.2. I am stuggling with part B of the question which asks us to find diL(0+)/dt, dvC(0+)/dt and dvR(0+)/dt. My attempt can be seen below. Before t=0 the 4A current source is not present and thus it is an open circuit. A capacitor acts as an open...

Regarding the equivalence principle of GTR, inertial mass and heavy mass are comparable, and are causing identically effects on mass objects. The pseudo force of inertial mass could be experienced in an accelerated frame of reference. In that point the "Force" appers, while energy is...

I'm looking for a source that fully derives the complete formula for the surface area of a general (triaxial) ellipsoid. I'd prefer a source that has more than just a full derivation, but also has a fair amount of prose discussion on this topic. Some historical context would be nice, as well...

Attached is the section from the book. I am doing section 31.3 We know that an AC source gives a sinusoidal varying current, and as far as I know its always given by ##i(t) = Icos(wt)##. Its like we take the current to be the base of all other quantities, so we use it to derive everything else...

This is actually right at the start of another derivation, but I can't understand how the author gets the formula for ##q##. So the discharge per unit thickness is the circumference of the circle, multiplied by the velocity at that point (at ##r##)? I thought the formula for flow rate was...

I'm looking for a book series tabulating various mechanical and material properties for metals and alloys. There is a book series called "Thermophysical Properties of Matter" and it details the thermophysical properties of hundreds of elements and compounds (even including some obscure uranium...

When I see discussions about quasar redshift, exactly what are they talking about? I assume a quasar is similar to a black hole, so emits little radiation from the main mass. The light from a quasar comes principally from its jets of accelerated material, no? Which means the jet pointed...

The article I first read which discusses this topic is: "IDing Mars' Dust" by Dale Keiger Johns Hopkins Magazine Volume 70, Number 4, Winter 2018 Page 20 The principle researchers are Assistant Professor Kevin Lewis of Earth and planetary sciences in the Krieger School, and postdoctoral fellow...

I am thinking of doing a DIY project in which one sub-task would be to dynamically balance a small assembly that will be spun up by, for example, a small motor taken from a DVD drive. As a test case, here is a setup where we would like to adjust screws S1 to S6 such that the cylinder is...

In my new novel, Handwavium, renowned genius physics Professor Samuel Clements Silver has created a prototype gravitational wave radio. For plot purposes, the protagonist needs to use the signal to triangulate his location. I know LIGO has three detectors and have seen reports of sources like...

C= mirror center O = vertex I don't know if the design is right, if someone can show me the correct one. I also don't know how to proceed in geometry Solution: Lf / ( L - f( 1 + d/D))

Hi, I've been reading about radiation detectors (manly form Knoll's book), but there is something I don't understand. Radiation detectors are of very different nature, but they all share a common process to detect a type of radiation: - I have a control volume - The incoming radiation interacts...

Hello all, this question really has me and some friends stomped so advice would be appreciated. Ok so, the relevant (dimensionless) continuity equation I have found to be $$\frac{\partial\rho}{\partial t} + (1-2\rho)\frac{\partial \rho}{\partial x} = \begin{cases} \beta, \hspace{3mm} x < 0 \\...

Hallo, can anybody help me and check if i have the right result: What is the minimum power P that a point source of radiation (I=8*10^(-7) W/m^2) at a distance of l=10 m from the listener must have in order to still be perceived? (Note: The emitted energy per area can be related to a spherical...

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All are used to finding the image charge induced by a source charge outside a conducting sphere. The solution is supposed to also work for the case where the source charge is inside the conducting sphere, in which case the sphere is now a conducting cavity. But the solution suggests the image...

The syllabus states : "Explain that the potential difference which is needed to apply across any electric circuit to flow current is supplied by an electric source". To explain this and make notes, I want to first understand what an electric source particularly is. And how all those electric...

My work seems to be wrong somehow since my answer is wrong, and I need your help to find out which part is going wrong for me :/ My work: 1. 2. 3. 4. 5. 6. (10/7)/(10/7+7) = 0.7627A, which is not the answer. May I consult where is the problem in solution? THanks