Source Definition and 1000 Threads

why the internal resistance of energy source or cell is shown in series for voltage source and in parallel for current source? thanks.

Consider the following circuit. Using superposition determine a) the magnitude and b) the direction of the current going through R_1 (is it away from node a?). Dtermine the c) magnitude and d) direction of the current through R_2 (is it away from node b?). e) Find V_{ab}. a) First, I will...

All electron flow nuances aside, let's look at simple circuit analysis. Hopefully you guys can clarify something for me. Say we have to drive an LED. We have a +5V source, a 3.4V forward voltage, and a 150 Ohm current limiting resistor: +5V --> Resistor --> LED --> GND Okay, so let's...

I know that nuclear fusion is the source of energy for our sun and most of the other stars. Neutron stars and white dwarfs have very high surface temperatures. What is the source of their energy?

Ive heard it said that electricity and megnetism are brought about by electromagnetic waves, but arent electric forces the cause of the other 2?

Homework Statement Suppose we have a circuit with the inductor, uncharged capacitor, ideal battery with emf E all in series. At t=0, the circuit is switched on. The following takes place sequentially: 1. Current at t=0 is max. Battery charges capacitor, current decreases. 2. inductor...

Homework Statement An emergency supply consists of a small diesel engine driving an alternator. The output of the alternator is rectified and smoothed to produce DC. This has has to supply 10 amps of 110V emergency lighting and charge a 110V battery of internal resistance 2 ohms, If the...

i understand that there are times when one should (on paper) pump a network of resistors, capacitors, and inductors with a 1 amp ac current source or a 1 volt ac voltage source in order to determine certain values within the system however, i am having trouble determining when i need to use...

Trying this again from a different angle... Let's say we have a 120 Volt AC source. We'll call it a generator. This generator is not touching the earth. Let's just pretend that it's suspended in mid air with nothing at all connecting it to the ground (the earth). On this generator, there...

Homework Statement Imagine that the source is to the right of the listener, so that the positive reference direction (from the listener to the source) is in the +\hat{x} direction. If the listener is stationary, what value does f_L approach as the source's speed approaches the speed of sound...

Suppose a capacitor is initially charged up to 2V, and then a 1V DC voltage source is used to discharge the capacitor to 1V, what is the energy consumption from the voltage source and what is the total energy loss? Assume the capacitor is connected to the voltage source using a resistor and...

Aim: To measure the acceleration due to gravity using a simple pendulum. [SIZE="3"]source of error 1. The length of thread between the bob and the coins is not measured by very accurate instruments. Since meter ruler has a large percentage error, as a result, it should be replaced by a...

Homework Statement A point source power outputs a power of 100 W. If a decibel reading of 118 dB is heard, what is the distance to the observer. Homework Equations I = P/(4*pi*r^2) The Attempt at a Solution This should be simple, but for some reason my numbers aren't matching up...

I hooked up four capacitors in parallel to a solar charger and found that they all acquired the same voltage. Why is this? I thought that capacitors took energy from the source, which would imply that the second, third, and fourth capacitor had less voltage than the previous one.

Homework Statement A two-point source interference pattern is generated by sources operating in phase at 1.0 Hz. The sources are 2.0 m apart and the wavelength of the waves is 0.60 m. At what angles, measured from the centre line of the pattern, are the nodal lines produced located...

Homework Statement An impedance 1000(1 + i) Ω (and note it contains an imaginary part) is connected across an AC voltage source of amplitude 10 V and frequency 60 Hz. Whatʼs the power dissipated during one cycle within the impedance? Homework Equations P = Re(V*I), where V* is complex...

I have just read the following line: A vacuum tube was a glass device which used filaments as a source of electronics and could control and amplify electronic signals. Please remember that I'm not a student of science or math, so please keep your reply simple as much as possible. What...

Hey all, I am trying to create a type of current source to switch between 10 mA and 1.4 A at some frequency. I have an idea to use a BJT transistor as a variable resistor in a LM317 (or whatever the high current version is) but am not sure how to do it. Any suggestions? This circuit is to...

hello.. this is my first post..forgive me if my question is wrong.. Why does a current source is modeled in such a way that it has its internal resistance in parallel ? Why can't it have its internal resistance in series ? The question may seem awkward , but please answer me.. thanks in advance..

Is it at all possible for the crystal sugar from one package to be qualitatively different from crystal sugar from another package (brand, etc.)? In other words, if I need sucrose for an experiment, could it affect the results if I use crystal sugar from different packages or of different...

Why does the small signal voltage gain collapse as we increase the AC input voltage? Voltage gain = Av = (output voltage) / (input voltage). Both small signal (AC). When you draw the small signal circuit using T-Model, you can find that Av= (gm * Rd) / (1 + gm Rs) gm being the the...

I was under the impression that a source transformation doesn't change a circuit at all, which I guess is an oversimplification. If you have a series RC circuit, with a DC voltage source, after the transients have died out, all voltage will be across the capacitor, and none across the...

Homework Statement Studying physics in High school, and for two years now we have covered two point source interference patterns with light, sound, and water wave in a ripple tank per say. The type of wave nor medium is necessary significant for me at the moment, but I am having trouble...

I have been thinking a bit about gravity in the classical Newtonian sense. So we know that the gravitational potential energy is inversely proportial to the distance that an object is from the object it is being attracted to. Thus if we form spheres of equal distance from a certain object we can...

Could the principle of Edge Tone used to create a frequency in the airflow of a musical instrument such as the recorder be used to impart a frequency on a much larger air stream? Ideally I would use it in something in the range of a 24" diameter fan with around 130 mph velocity and...

I want to keep all the species and radiation from plasma but not UV. Is there a way to design plasma source in a way that there will be no UV coming out?

Homework Statement Find ix i tried answering it i wasn't able to get it. The answer is given for basis by the way. (ix = 1.176 A) The image is attached to this post. Sorry for the inconvenience, it's my first time to post here. Homework Equations KCL(?) KVL(?) The Attempt at a...

Could anybody advise me, where i can read about how to calculate radiation dose from neutron source for human body. Excuse me for a second similar topic.

Homework Statement Homework Equations T = R*C The Attempt at a Solution I have no idea how to go about this. I know that T=R*C in a RC circuit

Hi All. Could you help me with following: Homework Statement We have: Neutron source Cf-252 Activity of Neutron source Cf-252 = 200 kBq The thickness of the protection of water-based = 30 cm Weight of the man = 80 kg Distance to a source = 1 m Questions How to calculate the absorbed...

Find the Thevenin Equivalent circuit between A and B the circuit is in the attachments... i don't know how to start and don't know what it meas "Between A and B" and i never encountered a problem with a dependent source. Thanks...

what is the difference between illuminant and source of light? What is the unit of illuminance and how can we calculate illuminance for IR light source?

Is it possible to use a system of reflections to direct most (if not all) of the light from a small luminous sphere to produce a thin beam that can focus to infinity?

Rindler (1977): Essential Relativity, 2nd ed., p. 249, deriving Maxwell's equations for orthonormal/inertial coordinate systems on Minkowski space: And A^{\mu\nu}_{\enspace,\nu} is the electromagnetic field tensor. Just checking if I've understood this right. Is the "4-velocity of the...

This kind of confuses me. You have a capacitor which has a voltage of 200 volts. Now when doubling the distance between the plates and adding a 100 V voltage source to it, it is said that the voltage between the capacitor plates stays the same, as in 200 V. I don't follow. Someone care to...

I would like to get opinions when calculating Source Impedance Ratio (SIR) on a Power System. Usually when calculating a three Phase fault it only takes into account positive sequence components, obtaining the source impedance ratio via the ratio of the source positive sequence component...

Not be able to feel the heat from afar, only up close? And heat can take form in all kinds of radiation right? So why is it that infrared radiation is always used to describe heat?

I apologize if this topic has been discussed before. Although it seems basic enough, I failed to find any discussion on it. I just can't seem to make sense of this simple thought experiment - traveling toward a light source. Lets say there was a star 1 light year away from Earth and I traveled...

In a different thread, PAllen posted a link to an interesting paper by Carlip, http://arxiv.org/abs/gr-qc/9909087 . PAllen's summary reads, in part: This relates to a question that has been bugging me for a while. In the case of a sinusoidally oscillating source, it's fairly easy to show...

Hi! So, I've got this problem, and it's doing my head in a bit; http://yfrog.com/mtthevcsj I'm not entirely sure where to begin with this one. I've tried a few things, and hit dead ends pretty quickly on all of them; trying to find vx, Voc, Isc, node analysis by treating terminal 'a' to...

Many groups have created Boltzmann solvers for photon/neutron transport simulations of reactors over the years - but has anyone released their code? I am specifically interested in Boltzmann solvers, not Monte Carlo based calculations. If you know of any open source projects, please let me know...

I was wondering why does a large, nearby light source produces a somewhat blurry shadow? While looking for a reply i found that when we are close to own own shadow, the outline of your shadow is sharp because the Sun is so far away. But i couldn't quite understand it.

Why is the voltage gain of a common source MOSFET negative? I have a schematic below and I get the voltage gain to be -gm(ro||Rd). I say that is what I get, but the truth is that is what my professor said we should get. I do not understand why the Gain (Av) is negative. It will go a long...

Before they can't hear the sound, assuming that the person can hear it very clearly as long as the frequency is within the range the human ear permits?

an application I'm working on requires 1.35 yoctoamps with a tolerance of + or - 0.10yoctoamps. Any current-source reccomendations?

Homework Statement We are going over gain, Gm, Ro, and Rin for MOSFETS. We are told to know and memorize certain equations and how to get these equations. In this particular problem we are told to find voltage gain by analyzing small signal. My professor gave this as the answer: (-gm*...

i know that motion of source can change the frequency of wave. constant speed motion will not change the wave progagation relative to water itself.but from the point of a observer at speed 0, the propagation speed will change. so my question is what will happen to frequency? thanks for help...

What is inertia? What is its source? Is inertial mass mass? Do gravitational mass and inertial mass have the same sign?

In an example in my book (Uni. physics), there's a circuit with emf = 12V, internal resistance, r = 2 Ohm, and no external resistance, R = 0, short circuit. What I don't get, is that it says that across the terminals, the potential difference between these points must be zero since there is no...

Can anyone recommend a white light source to be used in a cryostat down to 77 K? We are using it in temperature-dependent studies of PV devices. Currently we have an incandescent bulb which has shifted its spectrum towards red over time and we're looking for a replacement. It would be nice to...