In[]:=
Manipulate​​Row​​Module{norm,charges,field},​​norm[vec_]:=
Total[
2
vec
]
;​​charges={{q1,{1,1}},{q2,{0,-1}},{q3,{-1,1}}};​​field=
3
∑
i=1
charges〚i,1〛({x,y}-charges〚i,2〛)
3
norm[{x,y}-charges〚i,2〛]
;​​{VectorPlot[field,{x,-2,2},{y,-2,2},PlotLabel"Electric Field for Three Point Charges",VectorScalingAutomatic,VectorColorFunctionScaling->False,PlotLegends->Automatic,​​Epilog{Red,PointSize[0.02`],Table[Point[charges[[i,2]]],{i,1,Length[charges]}]},ImageSize->Medium],​​StreamPlot[field,{x,-2,2},{y,-2,2},PlotLabel"Electric Field for Three Point Charges",StreamColorFunctionScaling->False,PlotLegends->Automatic,​​Epilog{Red,PointSize[0.02`],Table[Point[charges[[i,2]]],{i,1,Length[charges]}]},ImageSize->Medium]}​​,​​{{q1,-0.5},-2,2},{{q2,0.25},-2,2},{{q3,0.74`},-2,2}
Out[]=
​
q1
q2
q3