Production and Propagation of Sound | Sound | Assessment | English | Grade 9

What is transported, when a sound wave travels from one place to another?

• Particles in the medium

• Air

• Energy

• Sound

Answer explanation

When sound waves travel from one place to another, energy is transported.

Which of the following statement is true about sound?

• Sound can be produced without vibrating an object.

• Propagation of sound can be pictured as propagation of density or pressure variations.

• The particles in a vibrating medium travels till it reaches our ears.

• Sound can be produced without the usage of energy.

Answer explanation

Sound cannot be produced without vibrating an object. So, option 1 is false. Particles in a vibrating medium do not travel till it reaches our ears. So, option 3 is false. Energy is used when sound is produced. So, option 4 is false. Propagation of sound can be pictured as propagation of density or pressure variations. So, option 2 is true.

Why is sound visualised as a wave?

• Because sound is a form of mechanical wave.

• Because sound needs a medium to travel.

• Because wave is a disturbance which gets carried forward during propagation of sound in a medium.

• Because rarefactions and compressions forms areas of high pressure and low pressure during the propagation of sound in a medium.

Answer explanation

Because wave is a disturbance which gets carried forward during propagation of sound in a medium.

Tags

NGSS.MS-PS4-1

Vibrating tuning fork is allowed to touch the surface of a hanging ball and the ball moves. What energy transfer takes place in this case?

• Heat energy to sound energy Sound energy to heat energy

• Mechanical energy to sound energy Sound energy to Mechanical energy

• Sound energy to Mechanical energy Mechanical energy to Sound energy

• Mechanical energy to sound energy

Answer explanation

Here, tuning fork gets mechanical energy when struck and then produces sound energy. Then the sound energy is transformed into mechanical energy when the ball moves.

Sound waves are _____ waves that are is produced due to _____.

• Disturbance, medium

• Mechanical, vibration.

• Disturbance, vibration

• Mechanical, medium

Answer explanation

Sound waves are mechanical waves that are is produced due to vibration.

Tags

NGSS.MS-PS4-1

Why are sound waves known as mechanical waves?

• Because sound wave needs a material medium for its propagation.

• Because sound wave are produced due to vibration.

• Because sound waves displaces particles in the medium in which it travels.

• Because sound wave is a disturbance.

Answer explanation

Sound waves known as mechanical waves because sound wave needs a material medium for its propagation.

Tags

NGSS.MS-PS4-2