UPSC ISS 2025 (Set A) – Q31 Solution

Bus Topology Concept Explained | Statistics Paper-1 (Computer Application & Data Processing)

The Indian Statistical Service Examination 2025 tested not only core statistics but also fundamental concepts from Computer Application and Data Processing.

One such conceptual question appeared in:

• Year: 2025

• Set: A

• Question Number: 31

• Paper: Statistics Paper-1

• Section: Computer Application and Data Processing

Let us carefully analyze the question.

The Question

Q31. In which of the following topology, all the nodes are connected to a single backbone cable?

(a) Mesh(b) Star(c) Hybrid(d) Bus

Correct Answer: (d) Bus

Detailed Explanation

The keyword in the question is:

“Single backbone cable”

This phrase directly points toward Bus Topology.

What is Bus Topology?

In Bus Topology, all computers (nodes) are connected to one main communication cable known as the backbone cable.

How it works:

• A single central cable connects all nodes.

• When a node sends data, the signal travels along the backbone.

• Every node receives the signal.

• Only the intended receiver accepts and processes the data.

If the backbone cable fails, the entire network collapses.

Why Other Options Are Incorrect?

(a) Mesh Topology

• Every node connects directly to every other node.

• No single backbone cable exists.

(b) Star Topology

• All nodes connect to a central hub or switch.

• Communication passes through the hub, not through a backbone cable.

(c) Hybrid Topology

• Combination of two or more topologies.

• Does not represent a specific backbone structure.

Concept Comparison Table

Topology	Structure	Backbone Cable?
Mesh	All-to-all connections	No
Star	Central hub device	No
Hybrid	Mixed topology	No
Bus	Single main cable	Yes

Why This Question Is Important for ISS Aspirants

Although ISS is a statistics-heavy exam, basic computer fundamentals are equally important in Paper-1.

UPSC often asks:

• Conceptual definitions

• Structural characteristics

• Fundamental IT/networking knowledge

• Terminology-based MCQs

This question tests:

• Concept clarity

• Basic networking structure understanding

• Ability to identify defining characteristics

Final Answer

✔ Bus Topology