Grade 6 Sound and Light Assessment

What is sound produced by?

• Heat

• Vibration

• Light

• Electricity

Answer explanation

Sound is produced by vibration. When an object vibrates, it creates pressure waves in the air, which we perceive as sound. Other options like heat, light, and electricity do not directly produce sound.

Which of the following is an example of a non-living thing that makes sound?

• Bird

• Music instrument

• Car

• Human voice

Answer explanation

A car is a non-living thing that produces sound through its engine and exhaust. In contrast, a bird, music instrument, and human voice are all living or animate sources of sound.

What is needed for sound to travel?

• Air

• Water

• Medium

• Vacuum

Answer explanation

Sound requires a medium (solid, liquid, or gas) to travel through, as it cannot propagate in a vacuum where no particles are present. Therefore, 'Medium' is the correct answer.

Which part of the human body produces sound?

• Stomach

• Vocal cords

• Liver

• Brain

Answer explanation

The vocal cords, located in the larynx, are responsible for producing sound when air passes through them, causing them to vibrate. The other options, such as the stomach, liver, and brain, do not produce sound.

What happens when you increase the force applied to an object that produces sound?

• The sound becomes quieter

• The sound becomes louder

• The sound stops

• The sound changes frequency

Answer explanation

Increasing the force applied to an object that produces sound typically results in a louder sound. This is because greater force causes more energy to be transferred to the medium, enhancing the sound waves produced.

Sound is produced when an object vibrates. What happens to the air around the object?

• The air moves in a circular pattern

• The air vibrates in the same way as the object

• The air heats up

• The air becomes still

Answer explanation

When an object vibrates, it causes the surrounding air molecules to vibrate as well, creating sound waves. Thus, the correct answer is that the air vibrates in the same way as the object.

Which of the following is TRUE about the propagation of sound?

• Sound travels through space without a medium

• Sound can travel faster in a vacuum

• Sound needs a medium to travel

• Sound travels only through solids

Answer explanation

Sound needs a medium to travel, such as air, water, or solids. It cannot propagate through a vacuum, which is why the statement 'Sound travels through space without a medium' is false.

Which of these objects produces sound by vibration?

• A car's horn

• A light bulb

• A rock

• A tree

Answer explanation

A car's horn produces sound by vibration of its internal components when activated. In contrast, a light bulb, rock, and tree do not generate sound through vibration.

If you struck a guitar string harder, what happens to the sound?

• The pitch becomes lower

• The pitch becomes higher

• The sound becomes louder

• The sound stops

Answer explanation

Striking a guitar string harder increases the energy transferred to the string, resulting in a louder sound. The pitch remains the same, but the volume increases, making the correct answer "The sound becomes louder."

What would happen if you removed the medium (air) from a bell jar while the bell rings?

• The bell would ring louder

• The bell would ring as normal

• The bell would not ring

• The bell would ring differently

Answer explanation

Removing air from the bell jar eliminates the medium needed for sound waves to travel. Since sound cannot propagate in a vacuum, the bell would not ring.