Question

There is a positively charged sphere A and negatively charged sphere B, such that they are brought in electrical contact by a copper wire.

Which sphere is at higher potential before electrical contact on the basis of convention?

Answer 1

Sphere A is positively charged and sphere B is negatively charged.
Both spheres A and B are brought in electrical contact by a copper wire.

On the basis of convention, positively charged sphere A is at higher potential before electrical contact.