Question

In a regular polygon of `n` sides, each corner is at a distance `r` from the centre. Identical charges are placed at `(n-1)` corners. At the centre, the intensity is `E` and the potential is `V`. The ratio `V//E` has magnitude
A. rn
B. `r(n-1)`
C. `(n-1)//r`
D. `r(n-1)//n`

Answer 1

Correct Answer - B
At the centre, the intensity is effectively due to one charge and the potential is due to `(n -1)` charges.
`therefore E = (KQ)/(r^(2)) and V = (k(n-1)Q)/(r)`
Hence `(V)/(E ) = (k (n-1)Q)/(r) xx (r^(2))/(kQ) = (n-1) r`