Bagaimana besar gaya listrik jika dua buah muatan di perbesar seperempat kali semula?

F = k × Q1 × Q2/r^2
r^2 = k × Q1 × Q2/F

r^2 = r^2
k × Q1a × Q2a/Fa = k × Q1b × Q2b/Fb
Q1a × Q2a/Fa = Q1b × Q2b/Fb
Q1a × Q2a/Fa = 1/4Q1a × 1/4Q1a/Fb
1/Fa = 1/16/Fb
1/Fa = 1/16Fb
Fa = 16Fb
Fb = 1/16Fa