4th Class Power Engineering Part B Practice Exam 2026 - Free Power Engineering Practice Questions and Study Guide

A single-shaft gas turbine is characterized by a unified design where the compressor and turbine sections are mounted on a single shaft. This configuration allows for direct mechanical connection between the turbine that drives the compressor and the compressor itself. As the turbine rotates, it powers the compressor, which draws in air, compresses it, and then mixes it with fuel for combustion.

This design results in several advantages, such as simplified construction and reduced weight compared to multi-shaft designs, where multiple shafts are used to connect different stages of compression and expansion. It also allows for more straightforward maintenance and operation, as adjustments made to the turbine affect the compressor immediately and proportionately.

In contrast, while multiple stages of compression are often present in gas turbines to enhance performance, they are not the defining feature of a single-shaft configuration. Higher operational efficiency can be a product of various factors, including the design and materials used, but it does not specifically define a single-shaft system. Reduced power output does not pertain to the structural design of the turbine, as single-shaft setups can offer robust performance levels.