CBSE class 8 sound

Sound is caused by:

• waves.

• vibrations.

• heat.

• air.

Elephants can make sounds of high intensity. These sounds will be:

• quiet.

• high.

• soft.

• loud.

The tweeting sound made by a small bird has a pitch that is:

• soft.

• high.

• low.

• quiet.

Frequency:

• is the amplitude of the vibrations.

• is measured in metres.

• is the number of vibrations each second.

• affects how loud a sound is.

Sound cannot travel though empty space because:

• air particles stay still.

• there are no particles to vibrate.

• particles pass on vibrations.

• electricity sends it through the air.

Which list is in the correct order to show the speed of sound in different materials, starting with the slowest?

• solids, liquids, gases

• solids, gases, liquids

• gases, liquids, solids

• liquids, solids, gases

What do all waves transfer?

• energy only

• energy and matter

• matter only

• energy and particles

What is the amplitude of a sound wave?

• its loudness

• the maximum distance the particles vibrate away from their starting positions when the wave passes

• the height of the vibrations

• how high or low the sound is.

The ear changes sound waves into:

• light.

• nerves.

• nerve impulses.

• heat.

Which part of the ear changes sound vibrations into signals sent to the brain?

• the cochlea

• the eardrum

• the auditory nerve

• the small bones