Option 1 is not true. Explanation & Key Takeaways: • A sound is a form of energy that produces a sensation of hearing in our ears. • Vibration is the physical phenomenon responsible for the production of sound. • Vibration is the rapid to and fro motion of an object. • Medium is necessary for the propagation of sound. • The substance through which sound is passed is known as a medium of sound. • The waves in which particles oscillate up and down and also the oscillation is perpendicular to the direction of propagation are known as transverse waves. • The waves in which oscillation of particles occurs in direction of propagation that is parallel to the line of propagation are known as longitudinal waves. sound is an example of longitudinal waves while light is an example of transverse waves. Hence statement 1 is not true. • The audible range of sound for a human is 20Hz to 20000Hz. Hence statement 2 is not true. • Non-periodic sound waves are term as noise. • The sound speed is 346 m/s. Related Concepts: Transverse Wave- • The waves in which the particles oscillate up and down and also the oscillation is perpendicular to the direction of propagation are known as Transverse Waves. • Light is an example of transverse waves. Longitudinal Waves- • The wave in which the oscillation of particle occurs in the direction of propagation i.e. parallel to the line of propagation is known as longitudinal waves. • Sound is an example of Longitudinal waves.