Fill in the blanks with suitable words.- Time taken by an object to complete one oscillation is called ___ .
- Loudness is determined by the ___ of vibration.
- The unit of frequency is ___.
- Unwanted sound is called __________ .
- Shrillness of a sound is determined by the ___ of vibration.
- Time taken by an object to complete one oscillation is called ___ .
- Loudness is determined by the ___ of vibration.
- The unit of frequency is ___.
- Unwanted sound is called __________ .
- Shrillness of a sound is determined by the ___ of vibration.
Solution and Explanation
(a) Time taken by an object to complete one oscillation is called time period.
(b) Loudness is determined by the amplitude of vibration.
(c) The unit of frequency is hertz (Hz).
(d) Unwanted sound is called noise.
(e) Shrillness of a sound is determined by the frequency of vibration.
Top Questions on Sound Produced by Humans
- In the following statements, tick ‘T’ against those which are true, and ‘F’ against those which are false.
- Sound cannot travel in vacuum. (T/F)
- The number of oscillations per second of a vibrating object is called its time period. (T/F)
- If the amplitude of vibration is large, sound is feeble. (T/F)
- For human ears, the audible range is 20 Hz to 20,000 Hz. (T/F)
- The lower the frequency of vibration, the higher is the pitch. (T/F)
- Unwanted or unpleasant sound is termed as music. (T/F)
- Noise pollution may cause partial hearing impairment. (T/F)
- CBSE Class VIII
- Science
- Sound Produced by Humans
- Sketch larynx and explain its function in your own words.
- CBSE Class VIII
- Science
- Sound Produced by Humans
Questions Asked in CBSE Class VIII exam
- If wheat is sown in the kharif season, what would happen? Discuss.
- CBSE Class VIII
- Basic Practices of Crop Production
Fill in the blanks using the correct form of the verbs in brackets.
My little sister is very naughty. When she ____ (come) back from school yesterday, she had _____(tear) her dress. We _____(ask) her how it had _____(happen). She ______(say) she _____ _____ (have, quarrel) with a boy. She _____ _____ (have, beat) him in a race and he _____ ____ (have, try) to push her. She _____ ____ (have, tell) the teacher and so he _____ _____ (have, chase) her, and she _____ _____ (have, fall) down and _____ _____ (have, tear) her dress.
- CBSE Class VIII
- The Best Christmas Present in the world
- In the tsunami 150,000 people died. How many animals died?
- CBSE Class VIII
- The Tsunami
- When he felt the earthquake, do you think Ignesious immediately worried about a tsunami? Give reasons for your answer. Which sentence in the text tells you that the Ignesious family did not have any time to discuss and plan their course of action after the tsunami struck?
- CBSE Class VIII
- The Tsunami
- Subtract 4p2q – 3pq + 5pq2 – 8p + 7q – 10 from 18 – 3p – 11q + 5pq – 2pq2 + 5p2q
- CBSE Class VIII
- Addition and Subtraction of Algebraic Expressions
Concepts Used:
Sound
Sound is a vibration that propagates the mechanical wave of displacement and pressure, through a medium can be of any matter. In other words, the sound is the thin line between Music sound and Noise.
Types of Sounds:
Sound can be divided into two types depending on its frequency. The following are:-
Infrasonic Waves:
- Infrasonic waves have a frequency lower than 20 Hz. Since it is below the human hearing range, it is inaudible to humans.
- However, several other living organisms use these waves to communicate, whales, sharks, elephants, hippopotamus, etc. these waves are also used in the scientific field, it is used to study upcoming earthquakes, volcanic eruptions, human heart rates, rock formation stages, etc.
Ultrasonic waves:
- Ultrasonic waves have a frequency higher than 20 kHz. Since it is above the human hearing range, it is inaudible to humans.
- These waves are used in the scientific field, it is used to study human heart rates, to take sonograms, navigation of directions, imaging things, uniform sample mixing, communication, testing of samples, etc.