Electronics Practice Test

The range of gain \( K \) considered in root locus analysis typically extends from zero to positive infinity. In control systems, the root locus is a graphical representation that shows how the roots of the characteristic equation (system poles) move in the complex plane as the gain \( K \) varies.

Starting from zero gain means that the system is at its initial state without any feedback, and as \( K \) increases, the poles of the system will move along certain defined paths. The analysis is primarily concerned with stability and the response characteristics of the system, which means examining gain values starting from zero and extending to infinitely large positive values.

Negative gain values and finite upper limits, as seen in some other options, do not accurately represent the typical application or consideration of the root locus method, where positive feedback is a primary focus for control system design and stability evaluation.