Which statement correctly describes a trough in a wave?

Which statement correctly describes a trough in a wave?

• A. It is the maximum value of the wave
• B. It is the minimum value of the wave
• C. It is the distance from crest to crest
• D. It is the lowest displacement point between successive crests

Answer: (D)

Think about a wave oscillating around its equilibrium position. The highest point is a crest, and the lowest point between two crests is a trough. So a trough is the lowest displacement reached between successive crests. It’s not about the distance from crest to crest (that’s the wavelength), and it’s not the maximum displacement (that’s a crest). The trough corresponds to the downward extreme of the wave’s oscillation, the lowest point in that passage.

Think about a wave oscillating around its equilibrium position. The highest point is a crest, and the lowest point between two crests is a trough. So a trough is the lowest displacement reached between successive crests. It’s not about the distance from crest to crest (that’s the wavelength), and it’s not the maximum displacement (that’s a crest). The trough corresponds to the downward extreme of the wave’s oscillation, the lowest point in that passage.