# Mass of spherical balls after adding charges

1. Aug 2, 2006

### Amith2006

# Two identical spherical balls A and B are given equal amount of positive and negative charge. What is the ratio of the masses A and B now?
a)Equal to one
b)Greater than one
c)Less than one
d)May be Greater than or Less than one depending on their sizes

2. Aug 2, 2006

### Jimmy Snyder

Are we to assume that A is given a positive charge and B given a negative charge? Even in that case, depending upon the method by which the positive and negative charges are given, the answer could be any of a, b, or c. I don't think the answer can be d because the balls are identical. Is there more information about how to give the balls their charges?

3. Aug 2, 2006

### dingsbunnyranch

When an object becomes charged, it either gains or loses electrons. Since electrons are negatively charged, when an object becomes negatively charged, it GAINS electrons, and therefore mass. So, mass B gains mass.
Similarly, when an object becomes postively charged, it loses electrons. So, mass A loses mass.

Therefore, the ratio of the masses is now less than one.