Question

When we pluck the wires in a sitar the motion of the wires are?
A. Longitudinal
B. Transverse
C. Sometimes longitudinal sometimes transverse
D. Electromagnetic

Answer 1

A motion is produced in the string when plucking the wires of a sitar which produces the sound. This leads to the motion of particles in the wire and this type of motion can either be longitudinal or transverse. If the motion of wire exhibits an up and down motion then transverse waves are produced and when the motion is parallel to the direction of propagation then longitudinal waves are produced.

Complete answer:
We are all aware that a sitar is a musical instrument and hence produces sound. Sound is a form of energy that is produced by the vibration of particles in a medium. This vibration can take place due to production of either of the two types of waves. One being transverse waves and the other being longitudinal waves.

Waves can exist in the form of either transverse waves or longitudinal waves. They need a material medium to propagate and the medium here is the wire of the sitar. Now, we need to find out what exactly happens when the strings of a sitar are plucked. When we apply an external force on the wire of the sitar by plucking its string a tension is produced in the string which is responsible for the vibration of the particles leading to the generation of sound.

This vibration of the particles occurs in an up and down motion in the wire which causes the sitar string to also move up and down producing a wave like motion. Knowing this, we must now determine whether the motion of the string corresponds to the property of transverse waves or longitudinal waves.

Transverse waves are said to be waves where the movement of the particles of the medium moves perpendicular to the direction of propagation of the wave creating a series of crests and troughs. Longitudinal waves are waves whose oscillations are along the same direction of travel and energy transfer.

In accordance with the property of sound waves we know that the propagation medium over here is the sitar string and hence we must now determine whether the motion of the particles is in an up down motion with respect to the string or in the same direction to the direction of propagation.

Since the wire of the sitar moves in an up down motion when plucked there is a creation of peaks and troughs in the wire and therefore according to its definition the waves produced in the wire are transverse waves since the particles are moving in a direction perpendicular to the direction of traversal of the wave.Therefore, motion of the wires in a sitar when plucked produces transverse wave motion.

Hence the correct option is option B.

Note: When the strings in the sitar are plucked the waves produced in the wires of the sitar are different from the waves produced in air. Longitudinal waves that are produced in air because of the sound generated by the sitar. Sound waves are longitudinal waves where the medium of propagation is air for these sound waves which are produced by the sitar.