Q.1. Fill in the blanks
(i) Quality of sound depends on ________ .
(ii) The speed of sound in a solid is ________ than the speed of sound in air.
(iii) Sound is caused by _________.
(iv) Pitch of sound depends on ________.
(v) Sound cannot travel through _______.
Q.2. If 25 sound waves are produced per second, what is the frequency in hertz?
(a) 25 hertz
(b) 50 hertz
(c) 75 hertz
(d) 1/25 hertz
Q.3. Which of the following vibrates when a musical note is produced by the cymbals in an orchestra?
(a) Stretched strings
(b) Stretched membranes
(c) Metal plates
(d) Air columns
Q.5. Frequency of ultrasonic sound wave is
(a) Greater than 20 HZ
(b) Greater than 20,000 HZ
(c) Greater than 2 HZ
(d) Greater than 2 MHZ
Q.6. Why are the ceilings of concert halls curved?
Q.7. What happens when sound travels in air?
Q.8. What is an echo? Name two areas of its application?
Q.9. What is SONAR? Write its working?
Q.10. How can ultrasound be used to detect the defect in metal block?
Q.11. Suppose you and your friend are on the moon. Will you be able to hear any sound produced by your friend?
Q.12. Sound requires a medium to travel? Justify experimentally.
Q.13. How does the sound produced by a vibrating object in a medium reach your ear?
Q.14. Why are sound waves called as mechanical waves?
Q.15. Explain how sound is produced by your school bell.
|1. What is sound?|
|2. How does sound travel through different mediums?|
|3. What is the speed of sound?|
|4. How does sound affect our daily lives?|
|5. What are the different characteristics of sound?|