Q16,Paper 3,J 13. In a fully connected mesh network with n devices, there are ________ physical channels to link all devices.

(A) n(n–1)/2 

(B) n(n+1)/2

(C) 2n 

(D) 2n

Answer A.

Explanation.

A complete digraph is a directed graph  in which every pair of distinct vertices is connected by a pair of unique edges

Triangle  need three edges to connect all nodes them selves..

Rectangle need 6 edges to connect all nodes themselves.

Pentagon. Needs 10 edges to connect all nodes themselves.

So n(n-1)/2.