Question

The following time-domain signals are associated with a discrete spectrum

A. [ ] Continuous Time (CT) aperiodic signals
B. [ ] Discrete Time (DT) aperiodic signals
C. [ ] Both CT and DT periodic signals
D. [ ] Finite Energy Signals
E. [ ] Signals which have an ROC including the unit circle

Answer 1

A discrete spectrum is associated with atomic and molecular spectra where electrons emit or absorb photons with specific energies when transitioning between quantized energy levels. In contrast, a continuous spectrum contains an uninterrupted range of frequencies or wavelengths.

Step-by-step explanation:

The student's question pertains to the properties of waveforms and their spectral characteristics. A discrete spectrum refers to a spectral distribution where only certain discrete frequencies or wavelengths are present, which is typically associated with atomic and molecular spectra. In atomic physics, a discrete spectrum arises because electrons orbiting an atom can only exist in specific, quantized energy levels. When electrons transition between these levels, they emit or absorb photons with specific energies, corresponding to discrete wavelengths or frequencies, resulting in a discrete spectrum.

In contrast, a continuous spectrum contains a continuous range of frequencies or wavelengths, without gaps, representing energy transitions that are not quantized. Both discrete and continuous spectrums can be observed in various physical phenomena, with discrete spectrums being a hallmark of quantum mechanical behavior in atoms and molecules.