Significance of resultant magnitude of the electric field in COULOMB for phasor mode of operation.

Dr. K.M. Prasad - Senior Application Engineer

Software: Coulomb™

In COULOMB, when the Operation Mode is set to Phasor (Single Frequency). The electric field components will be phasors viz:

• Εx = a + jb
• Εy = c + jd
• Εz = e + jf

Εmagnitude = g + jh = [(Εx)(Εx) + (Εy)(Εy) + (Εz)(Εz)]

Real Part {Εmagnitude} = g
Imaginary Part {Εmagnitude} = h
Magnitude {Εmagnitude} = sqrt [g*g + h*h]

All the above quantities (Εx, Εy, Εz, Εmagnitude ) are the rms (root mean square) values.

Let the unit vector of the normal to a surface/plane at the point of observation be {Nx, Ny, Nz}

The normal component of electric field is given by,

Εnormal = Nx*Εx + Ny*Εy + Nz*Εz = {(Nx*a+Ny*c+Nz*e) + j(Nx*b+Ny*d+Nz*f)} = m + jn

Magnitude {Εnormal} = [m*m + n*n]

Theoretically, on a conductor surface Εmagnitude = Εnormal. However, an insignificant difference (numerical noise) may exist between Εmagnitude and Εnormal. Therefore, Εmagnitude on a conductor surface is also the same as Εnormal.

In the model space at an observation point on an observation plane/surface, Εmagnitude is not equal to Εnormal. Therefore, in the model space at an observation point on an observation plane/surface, Εmagnitude is the rms value of the resultant magnitude of the electric field.