电偶极子的电场与电势

3.1主程序

clear;clc;q=2e-6;k=9e9;a=2.0;b=0;x=-6:0.6:6;y=x;

[X,Y]=meshgrid(x,y);

rp=sqrt((X-a).^2+(Y-b).^2);

rm=sqrt((X+a).^2+(Y+b).^2);

V=q*k*(1./rp-1./rm);

[Ex,Ey]=gradient(-V);

AE=sqrt(Ex.^2+Ey.^2);

Ex=Ex./AE;Ey=Ey./AE;

cv=linspace(min(min(V)),max(max(V)),51);

contour(X,Y,V,cv,'r-')

%axis('square')

title('\fontname{宋体}、fontsize{11} 电偶极子的电场线与等势线'),hold on

quiver(X,Y,Ex,Ey,0.6,'g')

plot(a,b,'bo',a,b,'g+')

plot(-a,-b,'bo',-a,-b,'bo',-a,-b,'w-')

xlabel('x');ylabel('y'),hold off

3.2 模拟图像