Question

The waves produced in spring by compressing a small portion of it and releasing are
A) Transverse waves
B) Longitudinal waves
C) Oscillatory waves
D) Non-material waves

Answer 1

Hint: Mechanical waves are disturbances in the matter and they transfer energy through the matter. Two types of wave motion for mechanical waves are: longitudinal waves and transverse waves. If the particle displacement is perpendicular to the direction of wave propagation, it is called a transverse wave. If the displacement is parallel, then it is called a longitudinal wave.

Complete answer:
If the particle displacement is parallel to the direction of wave propagation, it is called a longitudinal wave. These particles oscillate back and forth about their individual equilibrium positions. In a longitudinal wave, vibration or periodic disturbance takes place in the same direction as the wave propagation. A spring compressed at one end and then released experiences a wave of compression that travels along its length. Any point on the spring will move with a compression wave and then return along the same path and again reverses its motion. Sound waves moving through the air also compress and rarefy the gas in the direction of the sound wave. The primary seismic waves are also longitudinal.

Therefore, the answer is option B.

Note:
Longitudinal waves show areas of compression and rarefaction while traveling through any medium. The pressure is high when the particles are together and the region is known as compression. Similarly, the pressure is low when the particles are apart and the region is known as rarefaction. The wavelength of a longitudinal wave can be measured by measuring the distance from a rarefaction to the next rarefaction or from compression to the next compression.