Answer:
The new force is 1/4 of the previous force.
Explanation:
Given
---- 
--- 
Required
Determine the new force
Let the two particles be q1 and q2.
The initial force F1 is:
--- Coulomb's law
Substitute 2 for r1


The new force (F2) is

Substitute 4 for r2



Substitute 


The new force is 1/4 of the previous force.
It might be pull at a force of 100 N. I might be wrong.
When a wire is made shorter, the resistance decreases.
When a wire is made thinner, the resistance increases.
They are both formed by deposited river sediment.