Can someone explain this sentence in MOSFET design..
The Since the drain will be at a positive voltage relative to the source the two pn junctions can be effectively cut off simply connecting the substrate terminal to source terminal.
Hi everyone. I was trying to reproduce the calculation needed to include the QCD correction to the low energy electroweak Lagrangian. In particular I am looking at Peskin section 18.2. In equation 18.35 an extra minus sign appears on the numerator of the second fermion propagator.
Can anyone...
Hello!
In my studying of work I've always been told that work done (by what? ) = Force (component along its path) times the distance it moves. Mathematically, W=F.s ... My question here is what is the geometrical presentation of saying Force x Distance ... In other words, when we multiply...
Hey folks i got a doubt, Alcor is behind of Mizar,very near and why Alcor doesn't make part of the Ursa Major? i mean the Ursa Major is compost of 7 stars and alcor doesn't make part. thanks for the attention.
Hey people i have a doubt o try to be more specific this time, theia the planet collided with the Earth and created the moon this impact destroyed a large part of the Earth make a hole, what i like to know is how this hole who the planet Theia create on Earth disappeared, i mean the impact...
In First law of thermodynamics , work done by the gas is given by pΔV .
I have few doubts regarding this-
1)Is 'p' ,pressure of the gas or external pressure of the surroundings ?If gas is expanding then surely gas pressure should be more than that of the surroundings and vica versa ...
Consider a mass M, suspended by a weightless spring (horizontally or vertically). If I apply a force on the mass M, it executes simple harmonic motion. My question is for small displacement (that is pushed or pulled) according to Hooke's law F=-kx, it is equal to force we applied right...
A standard way of plotting an S-N (fatigue strength vs no of cycles) graph is to start off by taking a value of Sm (for N=1000) cycles and joining it to the point depicting Se(Endurance Limit). Now we commonly take Sm= 0.9Sut for steels. Now I was wandering, before you actually get to use the...
Lets say we have a beam which is simply supported at the two extreme ends(support conditions don't matter in my question). A concentrated transverse load is applied at the halfway point. Now let's say we take a section at x= L/3 where is L the length of the beam. Now we know that transverse...
It is generally said that centripetal acceleration is directed towards the center of the circular path along the radius. So can we say that centripetal acceleration is a linear acceleration. Is it or can it be represented along a straight line. I had a question in my exams. A kid is rotating a...
I have a question, according to rules for the sign of x and y-acceleration; when I should use the negative sign for gravity (g) in a problem, because it's confusing since I've seen that according to my textbook when an object is free falling g is negative (therefore acceleration is -9.8 ms^-2)...
Hi All,
I studied about Michelson Morley experiment in my graduation in the compulsory Physics paper. I had Computer Science major(not a Physics guy:frown:), anyways this question came in my mind during my graduation time and may be because of my misinterpretation however couple of days ago...
Homework Statement
I am having a few doubts while writing relationship between angular speed and linear speed ,in the reference frame of a moving observer .
Suppose at an instant, car A is heading towards car B with velocity 'v'. Car B is moving towards right with velocity 'u' ,i.e along...
I am doing a project of an entity relationship model and a doubt came: Should repeated attributes of the entities be shared? Or I must reproduce these to every entity? In another words, if two of my entities are books and magazines, shall I have a single publisher attribute, or one for each?
A car travels due east with a speed of 50.0 km/h. Raindrops are falling at a
constant speed vertically with respect to the Earth. The traces of the rain on the
side windows of the car make an angle of 60.0° with the vertical. Find the
velocity of the rain with respect to (a) the car and...
Hello guys,
I'm not getting the output of the diode logic circuits:
http://upload.wikimedia.org/wikipedia/commons/1/1f/Diode-OR2.png
If both inputs are 1, then there is current across the diodes then the output is 1, but shouldn't it drop because of the resistor R?
If both inputs are...
Hi all,
Only few days back I got the idea of probability density function. (Till that day , I believed that pdf plot shows the probability. Now I know why it is density function.)
Now I have a doubt on CTFT (continuous time Fourier transform).
This is a concept I got from my...
I am still in the first few pages of my differential course. I just passed through the term equilibrium solution. Apparently, it meant for me as when the solution of the DE is zero. For example, dv/dt= 9.8-(v/5) ... has an equilibrium solution of 49 where dv.dt is actually zero. Is this the...
When the limit of a function turns out to be infinity ,how should we interpret it ?
For ex. we have \lim_{x \to 0}\frac {1}{x^2} = \infty
What does this mean ?
Does it mean that the limit is ∞ or does it mean that the limit does not exist as ∞ is not a number ?
I would appreciate if...
I have a basic doubt on application of work energy method,
1. Can I apply work-energy method (i.e. work done equals to change in kinetic energy(KE)) for a body sliding down the inclined plane? If yes, while solving the problem i should use only change in KE or sum of change in KE &...
Hello,
I have a doubt on how to differentiate a complex function f:ℂ→ℂ defined as follows: f(z)=zz^* where the * stands for complex conjugation.
According to this source (at the very end of the Section, where it says: "...As this is a complex value, G*(f) acts as a constant...") the result...
Book: Classical mechanics (textbook) by Douglas Gregory (cambridge publications)
Law of mutual interaction states that when two particle (let it be P1 and P2) interacts, the particle (P1) induces an instantaneous acceleration (a21) on particle P2 and the particle P2 induces an instantaneous...
Newton's laws of motions are not applicable in Non-inertial frames of reference which means only mutually accelerated frames of references, My question is how can we apply Newton's laws of motions for practical experiments such as simple pendulum, motion of a ball, etc. conducted in near surface...
Dear Sir,
I am currently doing an advanced course in Quantum Mechanics. This current doubt of mine, I am unable to clarify it properly. It follows as:
Spin 1/2 particles reside in 2dim-Hilbert space( Spinor Space)...However, we talk about rotations of states in this space where the angle...
why are we considering speed is constant to find velocity a particle in uniform circular motion, is it possible for a particle in a circular motion to have constant velocity?
I have done quite a few introductory physics problems where calculus is involved .When refreshing the concept of work done by variable force,I find myself unsure about an application of calculus.The underlying concept which is puzzling me is at the very root of calculus .The work done by the...
When a positive point charge q is brought close to a neutral conducting spherical shell then negative charges will be induced on the part of the shell closer to q and equal positive charges will appear on side of the shell farther from q.I understand this part.
But if the conducting spherical...
Hi,
I understood the formal derivation of various QMC methods like Path Integral Monte Carlo. However, at the end of the day I still have a doubt on how to effectively use these techniques.
Given that we can interpret \beta in the quantum operator e^{-\beta\hat{H}} both as an inverse...
Hi,
What would be the voltage developed across a Piezo-electric crystal, say Quartz of size 15 cm-length, width and 2 cm thickness, If I stand on it. My weight is around 75 kg :)
I have no idea how to calculate it.
I was dealing with the derivation of Stefan's law from Planck's law. In this derivation one gets to the following equation
\frac{xe^{x}}{e^{x}-1}=5
At this point most places I looked provide an aproximate numerical solution to this transcendental equation and carry on. But I wwas thinking...
I understand that the dielectric constant of a perfect isolated charged conductor is infinite when its placed in an electric field (generally uniform)... Now I also know that when a conductor is placed between a parallel plate capacitor such that the distance between two plates in those...
This may sound really silly but yeah, a plane mirror, and a white sheet of paper, both reflect all the wavelengths of light incident on them. So Instead of a plane mirror, if I use a white sheet of paper, Why don't I see a reflection of myself?
I have studied ray diagrams, and i know how an...
Homework Statement
Let ##f:\mathbb{R}^3\to \mathbb{R}^3## such that ##v_1=(1,0,1) , v_2=(0,1,-1), v_3=(0,0,2)## and ##f(v_1)=(3,1,0), f(v_2)=(-1,0,2), f(v_3)=(0,2,0)##
find ##M^{E,E}_f## where ##E=(e_1,e_2,e_3)## is the canonical basis.
The Attempt at a Solution
i see
##v_1=e_1+e_3##...
Hi to all, i will appreciate your help in this.
This is the situation:
I have a tank, with a water column in it. This tank at the bottom has an "ideal" seal (a seal that permit the passing of object from bottom to upwards, but not the water to fall down.)
In this system i have sphere with...
1. 2 questions, one asked for the temperature of the water max density and the other one a Potency question which the awnser was 1125...
Trying to be funny( hahaha funny as **** ) i wrote 1124,999... as the anwser, since 1124,999...=1125 but my prof. said it was wrong this statement in...
I have certain doubts with Lenz's Law. Now, consider a horizontal loop. If a magnet with N facing the entrance of the loop is moving towards the loop. By Lenz's, Flux has increased. Who has increased it. The magnet. We oppose the downward B by inducing the UPWARD B. Thus, I is clockwise (RHR)...
Doubt Concerning "The Selfish Gene"
In the first chapter of "The Selfish Gene", when talking about replicating molecules, Richard Dawkins writes:
"Can we reconcile the idea that copying errors are an essential prerequisite for evolution to occur, with the statement that natural selection...
I'm a biomedical engineering student interested in computational neuroscience, "the neural code" and systems neuroscience to be more concrete. The problem is in my country Mexico, master's degrees either focus in the mathematical side or the biological. What would be better to study a master's...
Homework Statement
Given the endomorphism ϕ in ##\mathbb{E}^4## such that:
ϕ(x,y,z,t)=(4x-3z+3t, 4y-3x-3t,-z+t,z-t) find:
A)ker(ϕ)
B)Im(ϕ)
C)eigenvalues and multiplicities
D)eigenspaces
E)is ϕ self-adjoint or not? explain
The Attempt at a Solution
I get the associated matrix...
Homework Statement
While solving problems ,during collision ,we neglect impulse of external forces like gravitational force , spring force , acting on the system .
The cases are
1) An object falling from a height on a pan attached to a vertically hanging massless spring and colliding...
Hey folks i have a silly doubt ^^ why when someone is in front of you is like this person position of the arms are diferent i mean if someone is in front of you the person arm is left and your is right and where this person right arm is your left arm, and both are directed north ?? thanks for...
"Inflationary paradigm in trouble after Planck2013"? I doubt it, but..
After all those reports that Planck2013 gave us a picture of the early universe perfectly consistent with a simple form of inflation, slow-roll inflation, now comes a preprint saying that the fine print is problematic...
well i am a starter in QM, i have 2 big doubts ! let me first tell what i understood ,
there is phsi which defines a state of a system, phsi times x is a position operator and phsi 's derivative of x multiplied by i h is its momentum operator ...
well then i operator these in phsi and what do...
I´m having serious problems with free gibbs energy equation. My main problem is that i don't know the meaning of TΔS that appears in free gibbs formula. I know that S is entropy and T temperature; but some books say that TΔS is energy lost or dispersal energy; energy unavailable to do work; but...
Hi PF,
I am trying out LM565 PLL IC and designed the basic circuit for checking free running frequency f0 (2.5 KHz). I verified the f0 by not giving any input signal (input pin floating, should I GND it ??)
Now the problem is that while sweeping the frequencies up and down the free...