GateAI
Discrete Mathematics

GATE CSE 2012 · Q26

MCQ2 marksMedium

Time

Which of the following graphs is isomorphic to

GATE CSE 2012 Q26 diagram

Select one answerSingle correct

Pick an option to check

Solution

Step-by-step verified solution

Official answer: B)

Discrete Mathematics

To check graph isomorphism between the given graph GG and the options, we examine the structural invariants:

  1. Vertex and Edge Count:

    • The given graph has 77 vertices and 77 edges.

  2. Degree Sequence:

    • The given graph consists of a 55-cycle with one vertex connected to 22 pendant vertices (degree 11).

    • The degrees of the vertices are: one vertex of degree 44, four vertices of degree 22 (forming a 55-cycle with the degree-44 vertex), and two vertices of degree 11.

    • Degree sequence: (4,2,2,2,2,1,1)(4, 2, 2, 2, 2, 1, 1).

  3. Analyzing Option (B):

    • Option (B) contains 77 vertices and 77 edges.

    • The central vertex has degree 44.

    • It is adjacent to two vertices of degree 11 (pendants) and two vertices of degree 22 that are part of a 55-cycle.

    • Hence, graph (B) is isomorphic to the given graph.

Try the question first, then check your work.

Think the official key or this write-up is wrong?

Report error or challenge

Examiner trap

The misconception this question tests

This Discrete Mathematics previous year question is Q26 of the GATE CSE 2012 paper. Find more GATE CSE PYQs on Discrete Mathematics in Engineering Mathematics, or browse all GATE CSE PYQs.

Free diagnostic

Where do you stand for GATE?

Take the 20-minute diagnostic: the 3 topics that cost you the most marks, and a rank range. Or sit 5 related Discrete Mathematics PYQs now with no account.

One GATE CSE PYQ every morning

An official question by email at 7 AM IST, with a link to its verified solution. Unsubscribe in one click.

Discrete Mathematics in GATE CSE

Discrete Mathematics has 50 GATE CSE PYQs across 23 papers from 2011 to 2026. 11 of them are 2-mark MCQs like this one, and GATE CSE 2012 has 2.

How GATE tests Discrete Mathematics

More from GATE CSE 2012

Share this solution

A plain-text card for WhatsApp or Telegram study groups.

GateAI solution cardGATE CSE 2012 · Q26 · MCQ

Which of the following graphs is isomorphic to

Topic-wise GATE CS PYQs with verified steps

Independent practice explanation verified by the GateAI team. GATE is conducted by the IITs; question text follows the official paper.