A tiny wave with a wavelength less than 1.73 centimeters, whose restoring force is surface tension, is called a Capillary Wave.

A tiny wave with a wavelength less than 1.73 centimeters, whose restoring force is surface tension, is called a Capillary Wave.

• A. Capillary Wave
• B. Deep-Water Wave
• C. Seiche
• D. Tsunami

Answer: (A)

Capillary waves are tiny surface waves in which surface tension is the restoring force. Surface tension dominates at very short wavelengths, so their wavelengths are extremely small—typically less than about 1.7 cm. When you observe a wave this small and its restoring force is surface tension, it’s classified as a capillary wave. Gravity waves, in contrast, rely on gravity to restore the surface and have longer wavelengths; seiches are standing waves in a closed basin, and tsunamis are long-wavelength gravity waves from large-scale displacement. So this description fits capillary waves precisely because of the short wavelength and surface-tension restoring force.

Capillary waves are tiny surface waves in which surface tension is the restoring force. Surface tension dominates at very short wavelengths, so their wavelengths are extremely small—typically less than about 1.7 cm. When you observe a wave this small and its restoring force is surface tension, it’s classified as a capillary wave. Gravity waves, in contrast, rely on gravity to restore the surface and have longer wavelengths; seiches are standing waves in a closed basin, and tsunamis are long-wavelength gravity waves from large-scale displacement. So this description fits capillary waves precisely because of the short wavelength and surface-tension restoring force.