Answer :
Potential is constant throughout the sphere. So, the distance we take is the radius of the sphere.
The electric potential inside the sphere at r < r is:
V =[tex]V_{a} +V_{b}[/tex]
= [tex]\frac{k(q)}{r_{a} } + \frac{k(-q)}{r_{b} }[/tex]
= kq [tex]\left[\begin{array}{ccc}\frac{1}{r_{a} }-\frac{1}{r_{b} } \end{array}\right][/tex]
Part b
The electric potential in between [tex]r_{a}[/tex] and [tex]r_{b}[/tex] is:
[tex]V = V_{a} +V_{b}[/tex]
[tex]\frac{k(q)}{r_{a} } + \frac{k(-q)}{r_{b} }[/tex]
[tex]= kp\left[\begin{array}{ccc}\frac{1}{r_{a} }-\frac{1}{r_{b} } \end{array}\right][/tex]
Part c
The electric potential inside the sphere at r < [tex]r_{b}[/tex] is:
[tex]V = V_{a} +V_{b}[/tex]
[tex]\frac{k(q)}{r_{a} } + \frac{k(-q)}{r_{b} }[/tex]
[tex]= kp\left[\begin{array}{ccc}\frac{1}{r_{a} }-\frac{1}{r_{b} } \end{array}\right][/tex]
= 0
A voltmeter is used to measure the potential difference between two points. A voltmeter has a high resistance and is connected in parallel with an electrical component that measures the potential difference. The net potential energy between two adjacent ions EN.whose values depend on the particular ionic system.
Learn more about The net potential here:- https://brainly.com/question/17596774
#SPJ4