Question

The column sum in an incidence matrix for a directed graph having no self loop is __________

(a) 0

(b) 1

(c) 2

(d) equal to the number of edges

My doubt is from Incidence Matrix and Graph Structured Stack topic in chapter Graph of Data Structures & Algorithms I

This question was posed to me in examination.

Answer 1

Correct choice is (a) 0

Easy explanation - Under every edge column there would be either all 0 values or a pair of -1 and +1 value exists.