Charged spheres attract each other when: - they are charged by the same object - they are charged after grounding - the air is dry - they are oppositely charged

Answer.

Charged spheres attract each other when: They are oppositely charged

Explanation

Like charges do not attract to one another, rather they repeal. However, recent research in physics and mathematics has shown the opposite in that at particular distances two spheres that have similar charge can possibly attract each other. Using the method of image technique to solve this problem, equal charges may attract only possible if the force of gravity  between the two charged bodies is way more than the electrostatic force of repulsion. This is to mean that equal charged spheres may attract if charge by mass ratio of the bodies charged is tending to zero.

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