Grade 4-Short test 2

Unwanted sounds are called _____________.

• noise

• music

Sound travel through ____________ to our ears.

• sand

• air

Identify the instrument where sound is produced when strings are stroked .

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• 

The sound travels fastest through _____________.Identify the medium from among the pictures.

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• 

A high pitch sound is made by ___________ vibrations.

• slow

• fast

When lined with materials ,steel and foam , steel gave a sound of 30dB and foam 8dB .Which among these is good at blocking sound ?

• Steel

• foam

A _____________ is used to describe how high or low a sound is .

• volume

• pitch

Police Siren shows a noise intensity of 120dB whereas whisper shows a noise intensity of 30dB. Which sound among these is the loudest ?

• police siren

• whisper

Which among the instrument as shown in the pictures is used to measure the loudness of a sound .

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• 

Identify the type of circuit in the picture

• open circuit

• closed circuit