Question 10 A disk of radius b has a uniform surface charge density a. A small ball of mass 0.003 kg and charge + 2 C is at equilibrium at a distance 2b above the center of the disk. The charge density (in μC/m²) is given by: 7.82 4.93 1.23 2.46 ○ 3.72 2 pts +Q. M