Sign convention Definition and 66 Threads

Hey guys, So the sign convention for power is really confusing me. According to my knowledge, if a positive current is entering the positive terminal of an element, the voltage drops across the element and power is hence absorbed. Why does the question solution change the sign of the current...

The two standard conventions for the Minkowski metric are diag(1,-1,-1,-1) and diag(-1,1,1,1). The physics comes out the same either way, but I'm trying to make a list of the things that change depending on the convention you use. The Klein Gordon equation is one - with the "mostly plus"...

Homework Statement 1) Q. Which of the elements follow the passive sign convention? (psc) http://img401.imageshack.us/img401/3092/pic1r.gif v1 = +5 (V) i1 = +2 (mA) v2 = -10 (V) i2 = +500 (µA) v3 = +1 (V) i3 = -3 (mA) 2) Q. Which of the elements follow the passive sign...

Homework Statement One mole of an ideal gas at 300K expands isothermally from a pressure of 2x10^6 Nm^-2 to a pressure of 2x10^5 Nm^-2. Calculate the work done ON the gas. Homework Equations dW = PdV The Attempt at a Solution Following through the integral, it becomes clear that work is...

Homework Statement Determine which of the five sources in Fig. (attached) are being charged (absorbing positive power), and show that the algebraic sum of the five absorbed power values is zero. I've labelled how I'm referring to the sources in red...

Homework Statement I solved the problem, but upon further observation, I discovered that what I did didn't make sense. (these are rounded numbers, which shouldn't make a difference in my question) do = 13 cm (do is what I solved for in the problem, and according to the online system it was...

Homework Statement Calculate the power in the voltage source for this given circuit: Homework Equations P = \frac{V^2}{R} Or P = - \frac{V^2}{R} The Attempt at a Solution If we take the bottom left corner as the Initial node then and go around the circuit, then the voltage is a...

Hello, It's my first time login. I'm not good at english. Of course, I'm not native speaker. I wonder why we call 'passve' sign convention. have a good day. :)

What is the rationale for the sign convention in the space-time 4-vector? How is it related to the sign convention in the energy-momentum 4-vector, if at all?

[SOLVED] Sign Convention - Physics - Optics I was just looking at some sign conventions and I was wondering if this is true: Along the principle axis, if Si > 0, then does that mean you have a real, inverted image? Also along the principle axis, if So < 0, then does that mean you have a...

Hey guys, I need some help clearing up voltage signs, its always confusing me and I have my final this Friday. First off I'm not talking about voltage in a circuit, but rather if there is an electric field caused by a charge distribution. First off, I understand potential energy for gravity...

Hello: I need help determining if I and V assignments follow the passive sign convention. Here is the image of the circuit: http://img178.imageshack.us/img178/9572/pic1xu2.gif I know that in order for it to follow PSC the current I needs to flow towards +V. I'm not sure if that is...

This is my (error full?) understanding from my readings: 1. positive current flowing into a positive terminal of let's say a rechargeable battery is power being absorbed by the battery...so positive watts 2. negative current flowing into a positive terminal encounters the higher electrical...

Homework Statement http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam1/fa06 Homework Equations W =F*D The Attempt at a Solution I have it solved, now i thought - would be if i put work into the thing to move it but looking at it since both of...

In terms of the thermodynamic identity: dU = {\tau}d{\sigma} - pdV the term for the work done on the system (-pdV) must be positive if there is a compression, in which case dV would be negative, correct? If one wanted to write the identity in terms of the work done *by* the system, you...

Hi Could someone point me to websites with tutorials on the real-virtual sign convention for geometric optics (and possibly other known conventions too)? I've been googling for some time but the results aren't too satisfying. PS--Tutorials with mathematics are preferred... Thanks and...