The maximum displacement of particles from equilibrium position in a wave motion is known as

Step 1: Analyze the question The question asks for the name given to the maximum displacement of a vibrating particle from its rest (equilibrium) position as a wave passes.

Step 2: Explain the concept When a wave travels through a medium, the particles of the medium oscillate about their rest positions. The key terms are:

• Wavelength (λ): the distance between two successive points in phase, such as crest to crest. It is a distance along the direction of travel, not a displacement of particles.
• Amplitude (A): the maximum displacement of a particle from its equilibrium position. It is a measure of the wave's energy, since energy is proportional to A².
• Frequency (f): the number of complete oscillations per second, measured in hertz (Hz).
• Polarization: the restriction of a transverse wave's vibrations to one plane. It is a property of the wave's direction of vibration, not a size of displacement.

Step 3: Match the definition to the options

• A. Wavelength is a length of one complete wave, so it does not match.
• B. Amplitude is the maximum displacement from equilibrium, so it matches.
• C. Frequency is a rate (cycles per second), so it does not match.
• D. Polarization concerns the plane of vibration, so it does not match.

Step 4: Answer The maximum displacement of particles from the equilibrium position in a wave motion is the amplitude, which is option B.

Exam tip: Think "A for Amplitude = Altitude of the crest". Amplitude is measured from the middle (rest) line up to the crest, or down to the trough. It is not the full crest-to-trough height, which is twice the amplitude.