A sine wave is travelling in a medium. A particular particle has zero displacement at a certain instant. The particle closest to it having zero displacement is at a distance. (λ is the wavelength)

A sine wave is travelling in a medium. A particular particle has zero displacement at a certain instant. The particle closest to it having zero displacement is at a distance. (λ is the wavelength) Correct Answer λ / 2

Wave: 

• It can be defined as the transport of energy without the transport of matter.
• The properties of waves are:
• Wavelength (λ): The distance between two crests or troughs of a wave is known as wavelength. One wavelength equals the distance between two consecutive crests.
  • It is also the distance between two particles moving in the same phase. 
• Frequency (f): The number of oscillations or the number of waves passes a given point in one sec. Its SI unit is Hertz.
• Time period (T): The time is taken by the wave to complete one cycle.
• The relation between velocity, wavelength and frequency, and time period of a wave is
• Sound is a type of wave.

• From the above diagram, we can see that while going through the distance of its wavelength, the wave has cross-origin twice. 
• Also, the distance between two points is λ / 2. 

So, the correct option is λ / 2.