Answer:
d. (1/8πε0)Q/a
Explanation:
The potential difference [tex]v = \dfrac{1}{4 \pi \epsilon _0} \dfrac{Q}{r}[/tex]
[tex]= (\dfrac{1}{4 \pi \epsilon _0}Q) \dfrac{1}{r}[/tex]
Suppose we separate the quantity [tex](\dfrac{1}{4 \pi \epsilon _0}Q)[/tex] which is dimensionally and equally the same as [tex](\dfrac{1}{8 \pi \epsilon _0}Q)[/tex]. Then, we will have [tex]\dfrac{1}{r}[/tex] and [tex]\dfrac{1}{a}[/tex] as the same dimension.
Therefore, the correct option is:
d. (1/8πε0)Q/a
