The correct option is A-1, B-2, C-3, D-4
Explanation
Waves transfer energy through a medium via particle oscillation. Depending on the nature of the wave (transverse or longitudinal), specific terms describe the regions of maximum displacement or pressure variation. Sound waves are longitudinal waves consisting of density variations.- A. Crest (Matches 1): In the graphical representation of a wave (displacement-distance graph), the crest is the point of maximum positive displacement. It corresponds to the "peak" or highest point of the wave curve.
- B. Trough (Matches 2): The trough is the point of maximum negative displacement in a wave curve. It corresponds to the "valley" or lowest point.
- C. Compression (Matches 3): In a longitudinal wave (such as sound), a compression is a region where particles of the medium are crowded together. This creates a zone of high density and high pressure.
- D. Rarefaction (Matches 4): A rarefaction is a region in a longitudinal wave where particles are spread apart. This creates a zone of low density and low pressure.
Key Takeaway: Sound propagates through a medium as a series of compressions (high pressure) and rarefactions (low pressure). When plotted graphically, compressions correspond to crests (peaks) and rarefactions correspond to troughs (valleys).