The display screen of a spectrum analyzer shows a graphic plot of which two signal characteristics?

The correct answer identifies the two fundamental characteristics displayed on a spectrum analyzer: power and frequency. Spectrum analyzers are essential tools in electronics for visualizing the frequency content of signals. They convert signals into a frequency domain representation, where the x-axis typically represents frequency and the y-axis represents power (or amplitude).

In this context, power refers to the strength of the signal at different frequencies. When a signal is analyzed, the spectrum analyzer offers insights into the signal’s spectral components, allowing technicians to assess issues like distortion, interference, or frequency allocation.

Considering the other choices, while frequency is a common aspect for display, power is the relevant factor rather than alternatives like amplitude or phase, which do not provide the same detailed view into the signal's behavior across its frequency range. The other signal characteristics mentioned—such as wavelength and signal-to-noise ratio—are important in various contexts but are not directly represented on the basic spectrum analyzer display in terms of frequency analysis.