Answer:
The right option is C. 1/16 N
Step-by-step explanation:
From coulomb's law,
F = kqq'/r²................ Equation 1
Where F = force between the charges, q = first charge, q' = second charge, r = distance of separation between the the charges, k = constant of proportionality.
qq' = Fr²/k............... Equation 2
Given: F = 1 N, r = 2 cm = 0.02 m
Substituting into equation 2, to get the value of the product of the charges in terms of k
qq' = 1×0.02²/k
qq' = 0.0004/k.................... Equation 3
When they are moved to a new separation of 8 cm,
Then r = 8 cm = 0.08 m
F = kqq'/0.08².................. Equation 4
Substituting the value of qq' in equation 3 into equation 4
F = k(0.0004k)/0.0064
F = 4/64
F = 1/6 N
Hence the electric force on each of the is 1/16 N
The right option is C. 1/16 N