Question

What would make oppositely charged objects attract each other more?

increasing the positive charge of the positively charged object and increasing the negative charge of the negatively charged object
decreasing the positive charge of the positively charged object and decreasing the negative charge of the negatively charged object
increasing the distance between the positively charged object and the negatively charged object
maintaining the distance between the positively charged object and the negatively charged object

Answer 1

Increasing the positive charge of the positively charged object and increasing the negative charge of the negatively charged object.

Reason: Coulomb's law gives the force magnitude F = k |q1·q2| / r^2. Increasing the magnitudes of q1 and q2 increases the numerator and thus increases the attractive force. Decreasing the charges lowers the force, increasing the distance lowers the force, and keeping the distance the same leaves the force unchanged.