2. A uniform spherical ball of volume charge is described by \rho_{v}=\left\{\begin{array}{ll} K, & r \leq a \\ 0, & r>a \end{array}\right. where K is a constant. In addition, a

point charge Qo resides at the center of the ball. What is the value of Qo if E vanishes for all r> a?

Fig: 1

Fig: 2

Fig: 3