Mode Definition and 295 Threads

Homework Statement Hey guys. The title says it all pretty much. We need to find the normal mode frequencies of a driven/forced system containing 3 equal masses connected by 4 springs of equal spring constant k. Homework Equations F=m\ddot{x} Spring potential V = 0.5kx^{2}...

What is an "Optical Mode". I've been reading a lot of solar cell articles, especially those having to do with nanophotonics. There is a term that I keep running into, 'optical mode', but I've yet to find an explanation that I can visualize or understand. What exactly is the "mode" being used...

Question about continuous conduction mode converter I have a few quesitons about CCM converters I have posted a basic schematic of the circuit in question as an attachment. The circuit is a series LC circuit in which the inductor and capacitor charge during the on time. During the off time...

Homework Statement The number 15 is added to each of the biggest 150 numbers in a distribution of 301 numbers in other words n=301 A. How does this addition affect the median of the distribution B. how does this addition affect the mode of the distribution C. How does this addition affect...

Question about the "register plus immediate" addressing mode Homework Statement The question: "Why does adding addressing modes like register plus immediate to an instruction set architecture tend to improve performance?" The answer: "Adding additional addressing modes to an instruction...

How do you characterize an antenna in receiving mode? The book said a LHC antenna in transmitting mode is RHC in receiving mode. Also if the antenna is LHC in transmitting mode, it's transmission characteristic is defined as \hat {E}_{(z,t)}=\frac{\hat {x}+\hat {y} j}{\sqrt{2}}. But the same...

I have a brand new HDMI cable that was successfully tested with another laptop but it doesn't work with mine. I tried everything but I only manage to get extended mode working which still doesn't have good resolution on my tv. On other resolutions it doesn't work and on duplicate mode none of...

I am looking for some comparison of feed thru caps, ferrite beads and common mode chokes. when to use which etc. Feed thru basically shunts noise to ground. But if the circuit ground to Earth is not so exactly low impedance, some of the noise will end up in the circuit. Isn't a common mode...

Can we simply understand a softened phonon mode as one having reduced energy/frequency? Does "soft" indicate smaller value of the spring coefficient like the k in f=kx, where f is force and x is displacement of a spring, so a "soft" spring has a smaller k value? Thanks...

Homework Statement Hi everyone! first post here :) Basically, the question is as follows: Consider a hydrogen fluoride molecule (atomic mass of H is 1g/mole and of F is 19 g/mole). 1. Write the energy of the system in terms of the displacements of both atoms. There are other questions...

hi in wave guide and transmission line i didn't understand what is the importance of TE11 mode ... any help !

i am beginner in transistors i can't understand common emitter configuration for saturation mode ,i am new in electronics and need help

Hello Everyone, I am working on DC-DC converters. The actual approach of my circuit is that to maintained the output voltage remains constant for both line and load regulation. So that, I added the feedback loop of my circuit from the load resistor. To maintained the constant output voltage...

Homework Statement The first vibrational band in the absorption spectrum of H2CO is at 28871 cm-1. The first two bands in the emission spectrum (from v'=0 level) lie at 27021 cm-1 and 24687 cm-1. Explain these observations. Determine the band origin of the electronic transition and the...

Hello, My question stems from a research project of mine involving taking the normal modes of clusters of molecules from a potential. I was curious of the interpretation that can be made of normal mode vectors at a non-equilibrium structure, i.e something following a MD trajectory beginning at...

I have been wondering about the physical reason why a TE wave that goes STRAIGHT through the waveguide(without any reflections) can't propagate and would like some one to clarify the same OK..so if i consider a UNIFORM PLANE TE WAVE that goes straight thorough, then by definition of uniform...

Suppose a person takes data (say counts per minute of cars going past his window), for a long time. Then he loses his data, but knows that he counted 5 cars more often than any other number. What is the likely range for the average count rate? I tried to solve this by saying the mode is 5, so...

Can you calculate the frequency at which a bond vibrates when you know what frequencies of EM radiation it absorbs? Using carbon monoxide as an example. It has a stretching frequency at around 2100 cm-1. In electron volts, that would be around 0.3 eV. If I'm not mistaken, this is the energy it...

Hi, I've already made a question and recently received a reply. My question is how does a microcantilever have a torsional resonant mode. We generally study a longitudinal mode, not so much considering the torsional mode. The man who replied to my question said "It's because of...

Homework Statement Evaluate the ratio of the power contained within a circle of radius W(z) in the transverse plane to the total power in the Hermite-Gaussian beams of order (1,0) Homework Equations P=\intIdA The Attempt at a Solution I have determined the ratio for the Gaussian...

Hi, I am correcting a Embedded C code which requires Burst sleep mode. This sleep period is purely depend on the user input cool time and this is really to coll the machine. I thought of using Sleep function for this user input time but is it able to respond to other interrupts in this...

I'm working on an analysis problem using Abaqus. I would like to compare my results with an exact equation. My problem is modeled as a simply supported beam with a lumped mass at the end. The equation that I'm using for the exact solution is as follows: k=3EI/L3 ωn=\sqrt{k/(M + 0.23m)} How do...

I have never been able to grasp why certain mode shapes are the way they are. For example, I ran a free vibration analysis on a vertical beam fixed at the ground. The second mode shape is vertically straight. This is the same case whether or not I have a lumped mass at the top of the beam. Any...

Let's say a shielded cable is in the vicinity of noisy environment with plenty of EMI. How to go about cancelling the common mode currents, so that the magnetic field gets cancelled. It's pretty simple in case of differential mode currents. The mag field from the forward current and return...

This isn't a homework question in its entirety, I'm just wondering what the difference is between a Mode ratio and a mode shape? I'm taking a mechanical vibrations course and trying to figure out what the problem is asking for when it wants a mode shape...

I am trying to determine the mode of operation for the following circuit and find the voltages and currents: I am given that β = 50 I know that VEC > VEC,sat for a transistor in active mode I applied KVL on the right loop and got: VCC = 300Ic + 1000Ic + VEC VEC = VCC - 1300Ic i'm...

As for transmission line(which operates on TEM mode), electric field is created by the opposite polarity of surface charge on both conductors, and magnetic field is by the electric current in both conductors. These two fields are perpendicular to each other, which makes "the" TEM mode. Then...

# of photons in a mode (in a blackbody) I've been going over a proof again concerning the thermal average number of photons in a mode of a cubical blackbody of length 'L' at equilibrium with a reservoir of temperature 'tau' (has a small hole in it, etc. etc. etc.) The logic went as usual...

Hi all, I have a doubt regarding saturation mode of BJT. Saturation occurs when both emitter-base junction and base-collector junction gets forward biased. For forward biasing a silicon p-n junction only 0.7V is needed. So is for emitter-base junction. But not for base-collector junction...

Hi, I'm trying to locate a formula for determining the radial breathing mode of a hollow cylinder. The dimensions of the cylinder of interest are approximately .5" OD x .4" ID x .5" L Any help would be greatly appreciated. Thanks!

I have been trying to figure out how to plot a differential equation using my TI Nspire with very little luck. I managed to find that I can set the graph of the calculator to a directional field but I am not 100% sure I am getting the right results. So I figured I would ask to see if anyone here...

Hi. In order to measure the I-V curve of a normal diode in pulsed mode, I set up the following experimental kit. The experimental results do not change with pulsewidth, which is quite long (us regime), and low frequency (200hz and less). An HP pulse generator is connected via BNC cable to an...

Homework Statement A cyclindrical pipe of length 29.5 cm closed at one end resonates with a tuning fork of frequency 864 Hz. Then mode of vibration of air in the pipe is(Velocity of sound in air=340m/s): The attempt at a solution V=Velocity, n=Frequency If l1 is the first resonating...

Replacing Monitors - "Cannot display video mode" I'm switching out my old CRT Compaq FS7600 monitor (for specifications: see the link below) for a dell flat screen monitor. Unfortunately, this monitor says nothing about the model type, and I don't have the box as I got this from a friend. The...

I tried simulating a simple synchronous generator driving a resistive load in isolated mode (not connected to the grid/infinite bus), using Matlab Simulink, SimPowerSystems. First I used, Input mechanical power of 1 pu, and output resistive Load of 1 Pu. And Excitation Field Voltage of 4 pu...

I'm trying to determine the circular mode frequency for an open-ended pipe using the following equation and could use some clarification: f = (t/(2*d^2))*SQRT(E/density) f - frequency E - modulus of elasticity d - mean diameter t - wall thickness My first question is; do I need to...

Do I take the derivative of the density fct and set it equal to 0, then solve for t?

Hi, I am a bit confusing on the mode function in MATLAB. I have look throught some books and say we can use mode function to find "the most show up value" and "show up how many times". For example : r = 2 2 3 3 3 3 4 2 1 the most show up value is...

I developed a COMSOL model and calculated the first 6 modes of vibration of cantilever beam. Later out of curiosity, I looked up some videos on youtube to see actual cantilever. I found this video which shows the first mode. How do you know that its first mode of vibration? More...

Homework Statement I have a luminosity prob distribution that i want to plot and find the expectation value and mode for. Homework Equations p(L)dL = A \frac{L}{i}^aexp(-\frac{L}{i}) \frac{dL}{i} A=const a= -0.7 i= 1.4e10 solar luminosity units lower limit = 1e9 solar luminosity...

Homework Statement Attached as pdf. Homework Equations Attached as pdf. The Attempt at a Solution I know that refractive index is given by n=\sqrt{\varepsilon} normally. But is it still the case when asked for n( \omega) ? If so, I've tried rearranging equation 3 for...

Homework Statement Where would you locate a small vent hole to encourage the third mode of an open pipe? The fourth mode? Homework Equations Hint: Where is a node of the desired mode? The Attempt at a Solution Does this mean 1/3 of the way down for mode 3 and 1/4 of the way down...

Homework Statement Just as a background this is my first time ever learning to program. I am in an engineering C++ class. I had to write a program that took in ten random numbers and then found the mean median and mode. I got the first two and was able to figure out how to sort correctly. But...

Hi I am using Ansys to find the natural frequency of a structure but this has meant that my understanding of vibrations has become unstuck. When I last studied natural frequencies, it was under free vibration. I formed the impression that one structure can have only one natural frequency...

Hello, I don't quite understand the buck converter in continuos mode ... looking at the graph for inductor current on wikipedia, at t=0, there is a nonzero inductor current, Imin ... how is this possible when the inductor current cannot change instantaneously (assuming it starts at zero...

Hi - I'm new here - I'm just writing a paper based on an acoustical analysis of a rock/pop performance venue in a college I work at, and I'm up to my uncertainties section. I've read up on uncertainties, and feel confident in working out uncertainties for simple additions, multiplications...

hi what is the exact definition of normal mode?

Hi, I am trying to control a voice coil motor's force, which is directly proportional to the current through its coil. The direction of the force needs to be reversed, so I thought an H-bridge would be a good way to do it. I have read a lot about H-bridges but I am still confused about a few...

If a TEM00 output laser source (regarding both cases of single frequency vs multifrequency) is used as input into a multimode optical fiber, is it possible for the output of the optical fiber to be multimode?

Hi everyone, I find the following table from WolframAlpha concerning the probability of various decay modes of the pion \pi^{+}. My question is: Are these probabilities calculated, or are they numbers from numerous experiments? Thanks,