Question

two point charges at a distance r in air exart a force F the distance at which they exart same force when placed in a certain medium
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Answer 1

Answer:

r/ [rootk]

Explanation:

F (air) = (1/4 pi eo) [qQ/r^2]  

F(medium) = (1/4 pi eo*k) [qQ/R^2]  

given> F(medium) = F(air)  

(1/4 pi eo*k) [qQ/R^2] = (1/4 pi eo) [qQ/r^2]  

(1/k) [1/R^2] = [1/r^2]  

kR^2 = r^2  

R^2 = r^2/k  

R = r/ [rootk]