What type of spectrum shows only certain discrete wavelengths?

• A. Continuous spectrum
• B. Power spectrum
• C. Line spectrum
• D. Frequency spectrum

Answer: (C)

A line spectrum displays only certain discrete wavelengths, which is characteristic of emissions or absorptions of light by atoms or molecules. In this type of spectrum, each line corresponds to a specific wavelength, indicating the presence of particular energy transitions within the atoms or molecules involved. These distinct lines are a result of quantized energy levels and provide a unique "fingerprint" for each element, making line spectra essential for the identification of substances in fields like chemistry and astronomy.

In contrast, a continuous spectrum contains all wavelengths within a certain range, without any gaps, appearing as a smooth gradient of colors. This type of spectrum is often produced by solid, liquid, or densely packed gases where many different wavelengths are emitted or absorbed simultaneously.

A power spectrum is a representation of the power of various frequency components of a signal and is often used in the context of analyzing sound or vibration.

A frequency spectrum, similar to a power spectrum, shows the distribution of power or amplitude across different frequencies but does not represent discrete wavelengths.

Understanding these distinctions is essential for interpreting different types of spectral data and utilizing them effectively in scientific analysis.