Ncert – class 8- science – Chapter 10: Sound 2 Welcome to your Ncert - class 8- science - Chapter 10: Sound 2 1. A musical instrument is producing a continuous note. This note can not be heard by a person having a normal hearing range. This note must then be passing through: vacuum empty vessel water wax None 2. The maximum displacement of a particle in a vibratory motion is known as Amplitude Wavelength frequency Time period None 3. Which of the following vibrating parts of instrument is not matched with the respective instrument None of the above Drum- Stretched Membrane Tabla - Stretched Membrane Mridangam - Stretched Membrane None 4. Which of the following vibrates when a musical note is produced by the cymbals in an orchestra? Air columns Stretched strings Metal plates Stretched membranes None 5. A sound wave has a speed of 200 m/s in a medium and it travels a distance of 1 m. What is the time taken by the wave to cross the medium 100 ms 5 ms 50 ms 10 ms None 6. A particle takes 0.01 s to complete 5 vibrations, what is its frequency 5 Hz 50Hz 500Hz 10Hz None 7. A particle completes one vibration in 2 secs. How long does it take to vibrate 25 vibrations 50 sec 5 sec 10 sec 25 sec None 8. An astronaut can not hear his companion's sound at the surface of moon because: produced frequencies are above the audio frequency temperature is too low during night and high during day sound wave does not propagate through vaccum none of the above None 9. Sound waves having the following frequency are audible to human beings: 5 cycles/sec 50,000 cycles/sec 27000 cycles/sec 5000 cycles/sec None 10. The loudness of sound is determined by the Product of amplitude and frequency of vibration The ratio of amplitude and frequency of vibration Frequency of vibration Amplitude of vibration None 11. Name the instruments for which more than one part is responsible for the production of sound. Violin Tabla Guitar All of the above None 12. A sound wave, whose time period is 3 s passes through a medium for 30 s. The number of waves that had passed through is: 1 wave 10 waves 5 waves 3 waves None 13. A chain of hydrogen bombs is being exploded every time in the sun due to the fusion process, yet you do not hear the sound, because. The sound so generated dissipates away The sound so generated is absorbed by various layers of the sun The sun is very far away The space between the sun and the earth is void None 14. The safe limit of loudness of audible sound is 120 db above 80 db above 120 db 0 to 80 db None 15. Match the following columns and select the correct option from the codes given below.Column IColumn II(i) Pressure(p) Pattern formed due to multiple reflections(ii) Decibel(q) Unit of loudness(iii) Richter(r) Force per unit area(iv) Kaleidoscope(s) Scale to measure the intensity of (i) - (p), (ii) - (r), (iii) - (s), (iv) - (q) (i) - (p), (ii) - (s), (iii) - (r), (iv) - (q) (i) - (q), (ii) - (p), (iii) - (s), (iv) - (r) (i) - (r), (ii) - (q), (iii) - (s), (iv) - (p) None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
