Changing the volume of sound

What is this?

• microphone

• amplifier

• headphone

• loudspeaker

What is this?

• amplifier

• microphone

• headphone

• loudspeaker

The microphone, the amplifier and the loudspeaker make a ___. It make the sound ___

• system sound/ louder

• system sound/ softer

• sound system/ louder

• sound system/ softer

What kind of variable are they?

• control variable

• independent variable

• dependent variable

• none of them

Mike are testing the loudness of clock sound through some materials. The materials consist of wood, paper, orange juice, carbonic gas in a balloon. The materials are

• control variable

• dependent variable

• independent variable

• none of the above

What is the best material for sound to travel through?

• iron

• oxygen

• water

• carbonic gas

Rearrange the letters to get a correct word:

fumefl

Rearrange the letters to get a correct word:

lisencre

Arrange the words to have a correct sentence:

wear/ in/ place./Workers/ear/sound/defenders/muffle/to/noisy

We fit ___ to cars, trucks and motorbike to muffle the sounds of their engines.

• earmuff

• silencer

• ear defender

• microphone