Reverse Definition and 296 Threads

I've run into a problem programming a computer simulation. I have a discrete grid of values and a point an the middle with a value and I need to take the value and put it into the grid. I've been working on the 1 dimensional problem, and I can't get it. I know it's something simple I'm missing...

In forward bias the supplied voltage is distribute among the resistor and the diode (diode and resistor are connected in series) but in reverse bias the Current across the resistor remain zero because the conduction starts when very high voltage is supplied ...am i right ? but why the Voltage...

hi am new here ... and sorry for my weak English i have a question and a problem in physics that i need to know it's solution i will give you the main idea without numbers and you can assume any numbers that you find it suitable for the problem... the problem say: if a small ball is...

When I was younger I drove stick shift cars. Reverse gear was always all the way over to the right and down in the cars I drove (MGB and Jetta). I'm car shopping now and thinking about getting a car with manual transmission again. I noticed that some have reverse gear down and right, but...

I'm interested in thing that are norms except for the fact that they satisfy the reverse triangle inequality ||x+y|| \geq ||x|| + ||y||. The obvious example is taking p-norms for 0<p<1. Does anyone know of others or if there's any theory developed on this topic?

Hi, I'm analyzing a laser diffraction experiment. Does Matlab has a reverse FFT function? Thank you Naftali

Using Methane gas as an example (CH4 gas), explain why one can not assume the heat of combustion is the reverse of the heat of formation. I can't find a decent answer to this anywhere.

Hi.Non-physics student posting here for first time purely out of curiosity. I was wondering if we could improve our ability to percieve high speed objects which move to fast to see, by, for want of a better phrase, using a big magnifying glass backwards. For instance, if a car moves down a 500...

why sometime we need to reverse the order of integration? and how to determine the new limit? for example: for integration of dydx, the limit of y and x: y=2x , y=2; 0<=x<=1. after we reverse the order become dxdy, how to determine the new limit of x and y?

Homework Statement Indicate which of the 6 LEDs are ON and which are OFF Homework Equations V=IR The Attempt at a Solution Okay, I know LEDs 4,5 and 6 will be ON and LED 2 and 3 will be OFF but what about LED 1? Because LED 2 has a very high resistance as it is reverse biased thus...

Hello Everyone, Thank you for the help! I'm trying to better understand the reverse piezoelectric effect. More specifically what the reaction of the material would be with an applied energy. Is there deformation or just vibration? Is it controllable? Is it repeatable? Does it diminish over...

Forgive me for the noobish question, but here goes. My objective is to feed the reverse saturation current in a circuit into a DAQ device for detection. However I want to amplify it from the micro to milli or ampere range before doing so, due to DAQ specifications. I'm confused as to how...

why there is sudden increase in the small reverse saturation current at the breakdown voltage?...

i know >>char(100) gives some kind of ascii letter as an answer my question is, is there a function to convert the ascii letter back to 100? Thank you! edit - The language is MATLAB

Many years ago we started broadcasting radio signals for terrestrial use which inadvertently also radiated out into space. Possibly a civilization with appropriate equipment many light years away could have already detected these signals. But recently things have changed. By some estimates...

There is nothing I have tell before I go about on this madcap search. The problem is that I'm only 12 and searching for a device (or a circuit) which changes, or swaps, polarities, every time the switch (a switch made from a phototransistor and a resistor, in essence, getting activated...

"Reverse Universe": In general, we could say that looking to the ultimate particles of matter, enough physical laws subsist in the reverse universe to determine, from the positions and velocities of all particles of matter at a given instant, the entire past and future of the universe. The...

Hi guys Let a single cylinder ic engine. Now when we start the engine , then depending upon the position of crank the last time we switched off the engine, it is possible it may rotate in reverse direction because piston just has to reciprocate so acco to crank position at rest it may move...

Among the physical laws it is a general characteristic that there is reversibility in time; that is, should the whole universe trace back the various positions that bodies in it have passed through in a given interval of time, but in the reverse order to that in which these positions actually...

Homework Statement Hi, I have a problem to find the reverse saturation current for a piece of diode. I have a question - given conductivity, a I-V curve with forward bias information (a table of I vs V values), how can i proceed? I have other information abt the diode such as its mobility...

Homework Statement i'm sorry i know I've been bombarding physics forums with questions but i need help :p using reverse product rule \int uv' = uv - \int vu' and say i have a*b i noticed my teaher said that a=u and b=v not v' and he simly made that into a v' by deriving. is there a point...

Homework Statement e^(x) + y = dy/dx, [-1,1], y(0) = 1, N = 4. Homework Equations The Attempt at a Solution h = b-a / N = 0.5 x0= 0, y0 =1 x1= 0.5, y1 = 2.472 x2= 1, y2 = 5.433 x3= 1.5, y3= 11.195 x4=2, y4= 22.146 ===================== These were the values I got for the...

Recently I was doing various equations in RPN to teach myself the notation. Everything went fine until I wanted to do a limit. How would one go about expressing limits (and any other operation that isn't addition, subtraction, division, or multiplication) in RPN?

URGENT: PM Generator in Reverse If you have a permanent magnet generator being driven by a turbine and the generator outputs some power level, how would the configuration of a generator change if it is suppose to drive a turbine's compressor stage with the same power? I think the meaning is...

For the decomposition of one mole of nitrosyl chloride, Delta H = 38kJ. NOCl(g)-->NO(g)+Cl2(g). The activation energy of this reaction is 100kJ. Calculate the activation energy for the reverse reaction in kJ. I attempted this question but cannot find the process or equation to finish the...

Okay, there are two different questions, but are answered the same way (I believe). Homework Statement (1)Which function has a derivative equal to ex sin 2x (2)Which function has a derivative equal to tan x * tan 2x * tan 3x The Attempt at a Solution I thought (since the teacher...

Iam sorry if it is a very basic question but iam unable to understand this if u take a common emitter configuration of npn transistor the emitter is common to both the input and output terminals and to operate in the active region 1. the emitter to base should be forward biased i.e n and p...

http://www.ucar.edu/news/releases/2009/arctic2k.jsp The associated albedo flip will amplify the warming.

Hi I have a 9v motor (can run to 24v). I need to control the speed of the motor and reverse the direction. I also wanted to control it with a duel-potentiometer, but i can't seem to find any way to do this. can someone help with a circuit diagram please? (This is my first time building a...

My employer operates a biological water filtration plant. The first stage of filtration has the raw water passing through a filter embedded with bacteria, the processes used here is aerated biological treatment where oxidizing processes (bio-oxidation) are used and the microbes gain energy when...

The original problem was as follows: Closed-loop system, with complete isolation. Salt water is green, fresh water blue, porous plug (AB) is red. Fresh water spills into the salt water column at C if the fresh water is lifted higher than the salt water, maintaining continuous flow...

I am making a circuit of a car toy. Actually, i have already done its first step. The next step i want to make a one which is able to reverse and i think i will need an amplifier which can work in both biases (foward and reverse). So do exist amplifiers that can work in reverse as well as in...

This isn't an engineering question, but I don't know which forum is better suited to ask. I pulled two AA batteries out of my daughter's toy this morning after it had been left running all night. One of the batteries read 0.80 volts, and the other read -0.24 volts! That's right, one was...

What is "reverse Hfe"? Hey everyone, I'm looking over a synthesizer schematic that has a 2SC2878 transistor in shunt with the main output - I think it's connected up in some kind of power on muting circuit for protecting speakers against turn-on thumps. Interestingly, this transistor has...

Hi I have been looking through my book, and even online for the answer because I don't understand why this happens, but I can't find the proper answer anywhere...can someone help me? Thanks.

Hi I have been looking through my book, and even online for the answer because I don't understand why this happens, but I can't find the proper answer anywhere...can someone help me? Thanks.

Homework Statement Seawater is approximately .60M NaCl. What is the minimum pressure that must be applied at 25 degrees Celsius to purify seawater by reverse osmosis? Assume i=2.0 for NaCl. Homework Equations Osmotic pressure = MRT R= gas constant, .0821 Latm/mol K The Attempt at a...

The magnitude of vector A is 35.1 units and points in the direction 301° counterclockwise from the positive x-axis. Calculate the x-component of this vector. So...35.1=sqrt(vx^2 + vy^2) and 301°= vy/vx How do I do this?

Hello, How can you reverse the orientation (handedness) of elliptically polarised light? Thanks! Graham.

In the textbook, it reads: the reverse of carnot cycle is just a refrigerator or heat pump. In this sense, except for the direction of carnot cycle is reverse, could I say the way to calculate the efficiency of the carnot refrigerator is the same? That is, could be still use \eta = 1 -...

Hi guys, suppose that we have list of numbers 83+115+156 = 354 mean = 354/3 = 118 how can we get reverse of that . Can recover the above three numbers (83,115,156) from 118 by doing some mathematical tricks ( subtraction/ addition) etc. -- Regards, Asif

HI My question is what would the outcome be if the twins started out in 2 ships traveling at uniform .6c relative to Earth and one of them then took her ship and traveled to Earth and back? Which twin would be older?

Reverse Twins paradox ? This may have come up before but I haven't seen it and don't know the answer. What if the twins started out in two ships moving together at relativistically significant velocity relative to earth. One of the twins then simply goes to Earth and back while the other...

Integral problem "reverse order" Greetings, This is from an online homework question: Evaluate the integral by reversing the order of integration. \int^{1}_{0}\int^{8}_{8y} e^{x^{2}}dxdy Although, I fail to see how this works, if I switch the order I get...

I have been trying the proof of the reverse triangle inequality for n+1 real numbers: |x-y1-y2-y3-...-yn| \geq | |x| - |y1| - |y2| - |y3| - ...-|yn| | I know the proof of the reverse triangle inequality for 2 real numbers and the triangle inequality for n numbers. can somebody help ?

Homework Statement Determine reverse sat current of diode. To show and explain approach. Given-IV characteristics of diode and tabulated values for forward bias voltage from 0-0.8v and corresponding current values. Homework Equations At which point do I need to consider to find the...

faraday's law states that if there is a change in the magnetic flux inside a conductor, a potential is induced across the ends. Is the opposite also valid, i.e. if I have a current carrying conductor with a constant potential applied across the ends, will there be a change in the magnetic flux...

Entropy is said to always increase. But do not green plants reverse entropy? Seems to me that everything they do increases order, down to the molecular level.

Homework Statement when chiral 2-bromobutane reacts with aqueous hydroxide ions, the optical activity of the product is reversed. Suggest why the optical isomerism is reversed. The Attempt at a Solution i have no idea... but i don't know if the fact that the hydroxide ion will attack...

I have an ackward question. I've been trying to device a circuit to reverse the pattern of a LED. Let me give you a quick rundown of my situation and my goal. As it stands now. Imagine a an alarm system. When activated a LED is lit 24/7. When a switch is triggered the led will blink...