The sketches I to IV in figure show sound waves, all formed in the same time interval. Match the diagrams with correct sentences. (I) (i) Note from a musical instrument (II) (ii) A soft note (III) (iii) a bass (low frequency) note (IV) (iv) A shrill note

(I) (ii) A soft note A soft tone has low amplitude and less loudness. Among all four waves, this one has lass displacement from the mean position. Hence, it indicates a soft note. (II) (iii) a bass (low frequency) note A bass note has low frequency. Among all the waves, this wave has less number in a given time i.e., it has low frequence. Hence, it represents a base note. (III) (iv) a shrill note Shrillness or pitch of a sound determined by the frequency of the wave. Shrillness is more for a high-pitched voice. Among all the wave pictures, here the number of waves is more for the given time. Hence, It shows a shrilled note. (IV) (i) Note from a musical instrument Music is a pleasant sound to hear. A musical instrument may contain more than one note at the same time. Hence, the above picture shows the note from a musical instrument.

Name the part of the instrument that vibrates to produce sound in: a violin an organ pipe a drum.

The stretched string vibrates to produce sound in a violin. The pipe organ is a musical instrument that produces sound by driving pressurized air (called wind) through the organ pipes selected from a keyboard. Stretched membrane vibrates to produce sound in a drum.