Waves — Important Questions

Point of zero displacement

A node is a point in a standing wave where the displacement is always zero, representing points of no movement.

v = λν

For a travelling wave, the speed equals the distance covered in one period, so v = λ/T. Since frequency ν = 1/T, this can also be written as v = λν. The relation links wave speed, wavelength, and frequency.

Phase change of π (180 degrees)

When a wave is reflected from a rigid boundary, it undergoes a phase change of π, causing a reversal in its displacement.

Difference between two close wave frequencies

Beat frequency is the absolute difference between two waves with slightly different frequencies, creating a periodic variation in amplitude.