If n=1 you divide by 2
If n=2 you divide by 4
If n=3 you divide by 8
so any n you divide by 2 to the power n
To solve the problem we will simply perform equivalence between both expressions. We will proceed to place your units and develop your internal operations in case there is any. From there we will compare and look at its consistency


At the same time we have that



Therefore there is not have same units and both are not consistent and the correct answer is B.
Answer: The initial force is reduced a factor 1/4 when the separation between charge is doubled
Explanation: As it well known the electric force between two charges is given by:
Finitial=k*q1*q2/d^2 where d is the distance between charges and k is a constant
if the distance is doubled this means 2*dinitial thus the new force is equal to F initial* 1/4
Answer:

Explanation:
It is given that,
Radius of the circle, 
The area of the circle is given by :



or

As there is no uncertainty given in the radius of the circle. So, the area of the circle is
. Hence, this is the required solution.