Case : Read the passage and answer the following question(s).
The electrostatic force on a small sphere of charge 0.4 µC due to another small sphere of charge –0.8 µC in air is 0.2 N.
What is the distance between the two spheres?
Answer & explanation
Correct answer: option 1
F = kq1q2/r2
r2 = kq1q2/F
F = 0.2 N ; q1 = 0.4 µC ; q2 = – 0.8 µC
r = 12 cm