Q 1 – Pitch of sound is determined by its
(a) frequency
(b) speed
(c) amplitude
(d) loudness
Q 2 – The frequency of subsonic sound is
(a) more than 20 Hz
(b) 100 Hz
(c) less than 20 Hz
(d) more than 20,000 Hz
Q 3 – Sound can travel through:
(a) gases only
(b) solids only
(c) liquids only
(d) solids, liquids and gases
Q 4 – The number of vibrations made by a vibrating body in one second is
(a) frequency
(b) noise
(c) loudness
(d) pitch
Q 5 – Vibration in a body produce:
(a) energy
(b) sound
(c) heat
(d) none of these
Q 6 – A shehnai produces sound from:
(a) vibrating strings
(b) vibrating membrane
(c) vibrating air column
(d) none of these
Q 7 – Drum produces sound from:
(a) vibrating membrane
(b) vibrating stretched membrane
(c) vibrating strings
(d) none of these
Q 7 – Drum produces sound from:
(a) vibrating membrane
(b) vibrating stretched membrane
(c) vibrating strings
(d) none of these
Q 8 – Frequency of oscillations is:
(a) the number of oscillations per minute
(b) the number of oscillations per hour
(c) the number of oscillations per second
(d) none of these
Q 9 – The unit of frequency is:
(a) hertz
(b) hertz /sec
(c) hertz / min
(d) hertz / hour
Q 10 – The frequency determines the of a sound.
(a) loudness
(b) pitch
(c) both loudness and pitch
(d) none of these
Q 11 – Fill in the blanks
- human beings sound is produced by __________.
- Sound of frequency lower than 20 Hz is called the __________.
- The __________ nerve is also present in the inner ear.
- Sounds which are unpleasant to the ear is called __________.
- Too much noise in our surroundings that causes discomfort is called __________.
Q 12– True or false
- All human beings can hear sounds of frequencies upto 60,000 Hz.
- The sound in a sitar is produced by plucking its strings.
- Sound cannot travel through vacuum.
- Sound does not need a medium for its propagation.
- The loudness is expressed in a unit called decibel.
Q 13 – What are infrasonic sounds?
Q 14 – State the differences between ultrasonic sound and infrasonic sound?
Q 15 – What are the methods to control noise pollution?
Q 16 – Define frequency
Q 17 – A string musical instrument was first plucked with a force of smaller magnitude and then with a force of greater magnitude. In which case would the instrument produce a louder sound?
Q 18 – Differentiate between musical sound and noise.
Q 19 – How is sound produced and how is it transmitted and heard by us?
Q 20 – On Ramesh’s 13th birthday, his father invited all his friends and their relatives. It was a big party with lots of food and DJs. Ramesh didn’t like the loud sound of DJs and asked his father to play it in a low volume so that their neighbours do not get much disturbed and people in the party can also enjoy the music. Ramesh’s father felt good for his wisdom and did as he said.
- Do you enjoy loud sound DJs in parties?
- Do you think when loud music is played in a party is acceptable to all the people living in , neighbourhood?
- How can you control noise pollution at your end?
- What value of Ramesh is shown here?
Q 21 – Suppose a bell is ringing in a vacuum. Will you able to hear the sound?
Q 22 – We have learnt that vibration is necessary for producing sound. Explain why the sound produced by every vibrating body cannot be heard by us.