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2answers
24 views

Would magnetic flux be necessary for analogous systems?

I learned about the analogousness between mechanical and electrical systems a few months back (with the help of Feynman). Yesterday, my professor was lecturing about this topic, when she told that ...
0
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0answers
46 views

can we get electrical energy from gravitational energy? [duplicate]

Now I'm trying to give an answer of the question. Satellite rotates about earth by the gravitational force of earth. Now if we place the satellite in such an orbit so that it rotate in opposite to ...
0
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2answers
17 views

How does electrostatic force affect electronic devices?

How does electrostatic force generated by two seperate plates having opposite charges affect electronic devices? I know that magnetic fields have some harmful effects to electronic devices but I am ...
0
votes
1answer
9 views

Since Synchronous machines are constant speed machines how are their speeds varying with variation in load?

I understand that the power output depends on torque angle. So how does an increase in torque angle cause the rotor speed to reduce? Aren't the synchronous machines supposed to be running at constant ...
0
votes
4answers
58 views

Why is capacitor used?

I don't quite get the practical use of a capacitor. The theory is fine, but in simple words please explain how, why and where capacitors are used? Is there any other equivalent circuit for capacitors? ...
1
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1answer
41 views

Differential Equations for Block Diagram of Satellite Attitude Control System

I am trying to understand the procedure to setup differential equations from a block diagram. The enclosed example is about the attitude control of a satellite. The ultimate goal is to find a ...
0
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0answers
51 views

Circuit analysis, calculating voltage across resistor [duplicate]

i'm solved this question, I'm sure that solution is right, but my instructor says that V1=116V, and also he said that he will not show how he get this result.Please help to identify who is right.
1
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1answer
27 views

Optical Waveguides with grating

I have some problems about mode analysis in grating-coupled waveguides,Would you please introduce me a useful book about wave propagation in these structures.
0
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0answers
49 views

Reflection & Transmission curves of waveguides

I have simulated a grating-coupled waveguide in Comsol Multiphysics, the waveguide consists of 2 dielectric layers and air as the cover of waveguide. I have excited the modes of this structure by a ...
0
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0answers
27 views

Rotating neutral for 3-phase system

What does it mean by oscillating neutral for 3-phase electrical system? Is it any effect of harmonic production due to magnetic core hysteresis nature? I have been searched a lot about this through ...
0
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1answer
101 views

Studying Quantum Electrodynamics?

As an electrical/computer engineer, I already have a relatively thorough understanding of classical electromagnetism. From what I understand though, classical EM is only an approximation to quantum ...
1
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1answer
35 views

Simulating electrical sublimation of aluminium foil

When i apply high voltage (through a capacitor bank) across an aluminium foil, it gets converted into plasma. I want to simulate this process and study the properties of the plasma produced ...
0
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0answers
27 views

Transformers rate equation

Going back to transformers after some years I realize they hide a possible missconception I'm not sure I really understand. It is not easy to find a full derivation of the well known relation ...
1
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1answer
74 views

How can current be a smooth curve?

The following is a graph of the current across some circuit element: Note how the current is treated like a smooth continuous function. Even in the analysis of things (i.e. analysis of the ...
0
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0answers
45 views

Charge Amplifier response and frequency response [closed]

I am getting ready for my final and have completed everything on my study guide except for two questions I cannot figure out. Here is the first question: I have gone through all my lectures and ...
6
votes
1answer
94 views

Random walks on resistive network

I have been referring to a paper http://arxiv.org/abs/physics/0405135 to determine the effective resistance using random walks for an infinite square resistive lattice Though the author seems to ...
0
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0answers
33 views

How do cathode ray tubes (CRT) synthesize colours?

I just read about how LCD displays were based only on black&white contrasts, and only colour filters on each subpixel generated the colour of a pixel. However, how does that happen for a CRT? Is ...
0
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0answers
18 views

How does band narrowing (heavily doping the emitter) affect the alpha F and alpha R in the Ebers-Moll model of a BJT?

I think that when the emitter is heavily doped, the bandgap is reduced which increases the reference forward current(current flowing through the E-B junction ) but the alphas themselves do not change. ...
0
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0answers
29 views

P-type MOSFET performance

I was reading somewhere that the (110) plane has the highest atomic density and is best for p-channel MOSFET performance. How high atomic density influence the performance of P-channel crystal?
0
votes
2answers
218 views

How do I combine three resistors which are in parallel with each other?

For this circuit (a and b are connected by a battery), Will I be able to find the total resistance of the circuit by adding resistors that are in series and combining resistors that are in ...
0
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0answers
158 views

Electric field intensity at the center of a small cavity in a large block of polarized dielectric

I'm having trouble with an exercise in my textbook. The question is: Determine the electric field intensity at the center of a small spherical cavity cut out of a large block of dielectric in which a ...
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1answer
28 views

What is the suitable temperature for a motor to work without failing? [closed]

How much body temperature can a motor withstand along with the ambient temperature to work without failing?
2
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0answers
67 views

Fermi Energy and the Electric Potential

In an extrinsic semiconductor the electric potential is: $$\phi = \frac{1}{q}(E_{\mathrm{F}} - E_{\mathrm{Fi}})$$ where $E_{\mathrm{F}}$ is the Fermi energy, $E_{\mathrm{Fi}}$ is the intrinsic Fermi ...
4
votes
1answer
85 views

Magnetic muscles [closed]

Consider two flexible sheets glued at the ends, with electromagnets attached to both of them, so that depending on the directions and strength of currents passing through them, the system could be ...
5
votes
2answers
170 views

Could we run an electric car on electric eels?

Could we run an electric car on a tank full of electric eels? I've heard electric eels are around 400 to 500 volts and can keep shocking for up to an hour. They also have a 10 volt system to sense ...
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1answer
117 views

Generators and electric motors

In a diesel generator, instead of using diesel engine can we use an electric engine and connect the motor and generator to the battery? will this make it an infinitely moving system or will the ...
0
votes
1answer
49 views

Applying more current? [closed]

An electric motor draws 20 Amps, when at maximum load of x. Can that value of current be applied even if the load was ten times less than x from a certain power source?
7
votes
2answers
150 views

Does a radio receiver add a load to the transmitter?

If I have a dynamo connected to a switch and a load (such as a light bulb), the load on the dynamo is increased when the switch is closed and the light comes on. The dynamo gets harder to turn. Is ...
0
votes
1answer
135 views

What is the difference between a battery and a “polarized” charged capacitor?

I know that the main difference between the two is that a battery can provide a constant voltage whereas a capacitor's voltage decreases as the charge stored decreases. But what about the internal ...
0
votes
1answer
80 views

Load on a generator

I am really stuck on this and I couldn't find any references on the internet regarding this. When a load is connected to a generator, why does the current drawn from the generator increase. Since the ...
0
votes
1answer
125 views

Magnetic core, and a DC solenoid

A DC solenoid creates a magnetic field B. A highly permeability magnetic core is added to solenoid to increase B. Now, there is change in flux, due to the increase in magnetic field. What would be ...
1
vote
0answers
70 views

What does “although electrons enter and leave the diode, charge is carried by holes in the p-type region” mean? [closed]

I read this in an electronics book but I couldn't understand it: The flow of current through a forward-biased diode may be summarized like this. Electrons pass from the external circuit and ...
-5
votes
1answer
136 views

traditional transformer design improvement [closed]

The traditional tranformers suffer a lot of losses in various forms, some of them are as follows : 1. Flux leakage 2. Eddy currents 3. Hysteresis Figure : But as we are taught induction we come ...
0
votes
1answer
341 views

Conservation of energy and ohms law in a step up transformer

In an ideal step up transformer with a constant resistance attached to the secondary coil, how is energy conserved and ohms law followed at the same time? $$\frac{V_p}{V_s}=\frac{N_p}{N_s}=\frac ...
0
votes
1answer
56 views

How to produce a bigger rotational velocity from two rotational velocities?

If I have two electronic motors, both running at the same voltage and current, delivering the same rotational velocity, how could I produce a bigger rotational velocity from them?
1
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0answers
375 views

Help making a solenoid engine [closed]

I am currently working on a school project and my aim is to build an electric motor using DC. I am looking at a design similar to this: Solenoid Engine and I have built majority of it however I am ...
1
vote
1answer
182 views

Do bifacial solar panels operate at lower temperature than normal solar panels?

Bifacial solar panels have a glass backplane instead of the usual aluminum and are designed to absorb and convert to electricity light incident on either face. Many manufacturers claim that their ...
0
votes
0answers
24 views

What is the necessity of expressing power gained by an amplifier in terms of decibels? [duplicate]

In engineering field the power gained by an amplifier i.e, the ratio of output power and input power expressed in terms of decibels i.e, $20 \log\left\lvert\frac{\text{output voltage}}{\text{input ...
1
vote
3answers
647 views

Would connecting p-type and n-type semiconductors work as a diode?

If we placed p-type and n-type semiconductors close enough to be touching (see fig. 1), would this arrangement work as a diode? ...
1
vote
4answers
2k views

Transformer: primary side & secondary side current 180 degree out of phase

I am a novice in electrical engineering. I notice that in transformer the secondary side current & current referred to as primary are 180 degree out of phase from each other. But why it is so, I ...
3
votes
1answer
287 views

How do High Electron Mobility Transistors (HEMT) work?

I am studying High Electron Mobility Transistors (HEMT), but I simply cannot understand how they work in the way described by the references I've read on the Internet. This is what I understand so ...
2
votes
2answers
175 views

Thevenin equivalent of a circuit

Ok so I can't post the image of my question and my attempt at it, so I would like to ask, if anyone knows the steps to simplifying a circuit with dependent current sources, independent voltage ...
5
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2answers
129 views

Layered CMOS structure question

I am trying to understand the workings of a CMOS image sensor. I understand that increasing wavelength results in an increased penetration depth in the silicon often used in CMOS image sensors. What ...
0
votes
1answer
78 views

Current in AC circuit

The problem is to find the current on the capacitor. $I''$ should be correct, but I don't know how to construct the formula for $I'$. I managed to get the value for $I_c$ using Thevenin and Norton ...
1
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2answers
278 views

Power transfer in a transformer

Can it be proved using the concept of induced emf that power supplied at the primary coil equals power consumed at the secondary. I tried following. Let primary coil be called 1 and secondary be ...
7
votes
2answers
2k views

Is it viable or possible to make your own transistor?

Just wondering if it is possible/viable to construct your own transistor, not small like todays, but the same scale as the one created at Bell Labs.
2
votes
1answer
453 views

How we approach RLC circult from RLGC model?

In the text, it introduces a practical model to investigate a transmission line (like BNC cable), it considers the transmission line has resistive $R$, inductance $L$, conductance $G$ and capacitance ...
2
votes
1answer
146 views

Application of plasma actuators for flow control of moving objects

I've recently been to a converence on plasma physics were, to my surprise, a lot of presentations were concerned with plasma actuator. Could someone, preferably in the field, tell me how long people ...
1
vote
4answers
1k views

When does Thevenin's theorem not apply (modelling a power source with a ohmic internal resistance)

Most physics text books say that a power source can be modelled as an EMF with a internal resistance. This is also know as Thevenin's theorem or Norton's theorem. However I have read in some sources ...
-1
votes
1answer
89 views

Differentiating a sinusoid [closed]

http://i.stack.imgur.com/ndLgm.png I don't see the how the author derived that $\frac { dv }{ dt } \leftrightarrow\overrightarrow { V } j\omega$.