Question

two point charge q1 and q2 at a separation r in vacuum exert a force on each other. what should be their separation in an oil of a relative permitivity 16 so that force between them remains same

Answer 1

F = kq1q2 / tr²     (let t = relative permitivity)(k = 9*10^9)
for vacuum t = 1
F1 = kq1q2 / r²
F2 = kq1q2 / 16R²
F1/F2 = 16R²/r²
R = r / 4

Answer 2

Answer:

The separation should be r/4 n an oil of a relative permitivity 16 so that force between them remains same .

Explanation:

F = kq1q2 / tr²     (let t = relative permitivity)(k = 9*10^9)

Now, for vacuum t = 1

F1 = kq1q2 / r²

F2 = kq1q2 / 16R²

So,

F1/F2 = 16R²/r²

R = r / 4

Thus, two point charge q1 and q2 at a separation r in vacuum exert a force on each other.