Question

The figure shows two identical spheres A and B carrying +4 V and -4 V potential respectively. Two spheres are put in contact. State which sphere will donate free electrons to the second sphere?

Answer 1

1. Electric field is from higher potential to lower potential and vice-versa if the charge is negative.
2. Since electrons are negatively charged particles, it flows from the sphere of lower potential to that of higher potential.
3. So electrons flow from sphere B to sphere A.