A small positive charge \(q\) experi- \(\quad \vec{E}_{1} \quad \vec{E}_{2}=2 \vec{E}_{1} \quad \vec{E}_{3}=3 \vec{E}_{1}\) ences a force of magnitude \(F_{1}\) when placed at point 1 in Figure Q20.18. In terms of \(F_{1}\) :

a. What is the magnitude of the force on charge \(q\) at point 3 ?

b. What is the magnitude of the force on a charge \(3 q\) at point 1 ?

c. What is the magnitude of the force on a charge \(2 q\) at point 2 ?

d. What is the magnitude of the force on a charge \(-2 q\) at point 2 ?