Answer:
a). The potential is highest at the center of the sphere
Step-by-step explanation:
We k ow the potential of a non conducting charged sphre of radius R at a point r < R is given by
![E=\left [ (K.Q)/(2R) \right ]\left [ 3-((r)/(R))^(2) \right ]](https://img.qammunity.org/2020/formulas/physics/college/qxfnht7os687gez3qiqdi0tu1osw6hunyj.png)
Therefore at the center of the sphere where r = 0
![E=\left [ (K.Q)/(2R) \right ]\left [ 3-0 \right ]](https://img.qammunity.org/2020/formulas/physics/college/o0agjzwsjh21a0098awbaa5e770yuk914i.png)
![E=\left [ (3K.Q)/(2R) \right ]](https://img.qammunity.org/2020/formulas/physics/college/3zqo1qas37cx4s3zy6iq8vmqat8d7n4vhk.png)
Now at the surface of the sphere where r = R
![E=\left [ (K.Q)/(2R) \right ]\left ( 3-1 \right )](https://img.qammunity.org/2020/formulas/physics/college/anf56u4tkkq3j9hd678jdcq8ekogby3pmk.png)
![E=\left [ (2K.Q)/(2R) \right ]](https://img.qammunity.org/2020/formulas/physics/college/e0gv7pty2l5tfyxg11f0s38qz1maib7uvk.png)
![E=\left [ (K.Q)/(R) \right ]](https://img.qammunity.org/2020/formulas/physics/college/bmzkf86ijkr8h3a4g84c1voj2gooaoqoid.png)
Now outside the sphere where r > R, the potential is
![E=\left [ (K.Q)/(r) \right ]](https://img.qammunity.org/2020/formulas/physics/college/ry9kkmoclwedkouhyri7nvs3di02n0ixcd.png)
This gives the same result as the previous one.
As
![r\rightarrow \infty , E\rightarrow 0](https://img.qammunity.org/2020/formulas/physics/college/gp3dlz368h6rnx92155ldrkvfm47ik56re.png)
Thus, the potential of the sphere is highest at the center.