Recent content by iochoa2016

Yes, I think you are right. Just triying to use energy to work out the Field. It was easy for the example below, but not so easy for the semicircle ring.

found this: along an axis pointing out the paper passing through the "O", V = K*lambda*pi * r /(sqrt(r^2+z^2)

This is how I calculate V: dV = k * dQ/r = k*r*d(theta)*lambda / r dV = k*lambda * d(theta) Integrating from 0 to pi V = k* lambda * pi.

k = constant, lambda = constant so V = constant, isn't it?

According to theory I should be able to get the Electric Field (E) from its pOtential (V) by doing the grad (V) so E = -grad(V), however, V is contant V = k*lambda* pi which results having E =0, but this is not right. What I am missing?? see figure below The answer should be Ex = 2*k*lambda / r...

Yes I have the book. I think I will do this expriment and cross check with experimental value

Electromagnetics by John D. Kraus

The book I was referring to is third edition. However just found out that edition 1 and 2 have special section about this method. My understanding is that the characteristic impedance can be determined using a multimeter. the section geometry of the cable has to be drawn on this paper.

Can someone provide more information about this method to measure chracteristic impedance using resistance paper?. Kraus' book claims that the characteristic impedance can be measured by simple dc measurement. It even shows a case to mesure the impedance of a coaxial cable with square outer...

Hi Thanks for your answer, great explanation but I still want to ask: When charge 1 is brought I guess we take this as a reference, so we stick this charge on position ##\vec{r}_1##. when charge #2 is brought to position ##\vec{r}_2##, how it is held in that position?, I visualize it that an...

I quite understand the fact the EPE (Electrical Potential Energy) of a system of two charges are U = k*qQ/r, Q is fix. however when it comes to three charges i get lost. because my reasoning is : if q1 is fix then the EPE of the system when q2 is brought is U2 = k*q1*q2/r12, when q3 is brought...

Hi, Thanks for the answers. Still is not clear for me the word "strength". Strength (as i understand) is the capacity of a mater to handle a certain stress. as E is a medium (field or substance) then its strength is defined as F/Q, so when a test charge Q is placed in the field, a force appear...

Electric Field Strength is defined in many books as F/Q, where F is force and Q is the test charge. but why is that? why not F/(2Q)? or F/Q^2?, is this word "strength" related to stress-strength as in mechanics?