Ncert – class 8- science – Chapter 10: Sound 2 Welcome to your Ncert - class 8- science - Chapter 10: Sound 2 1. The safe limit of loudness of audible sound is above 80 db 0 to 80 db above 120 db 120 db None 2. Which of the following vibrates when a musical note is produced by the cymbals in an orchestra? Stretched membranes Stretched strings Metal plates Air columns None 3. A particle takes 0.01 s to complete 5 vibrations, what is its frequency 5 Hz 50Hz 10Hz 500Hz None 4. 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 10 ms 100 ms 5 ms 50 ms None 5. The loudness of sound is determined by the Product of amplitude and frequency of vibration Frequency of vibration The ratio of amplitude and frequency of vibration Amplitude of vibration None 6. 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: wax vacuum water empty vessel None 7. A particle completes one vibration in 2 secs. How long does it take to vibrate 25 vibrations 50 sec 25 sec 5 sec 10 sec None 8. 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: 3 waves 10 waves 1 wave 5 waves None 9. Name the instruments for which more than one part is responsible for the production of sound. Guitar Tabla Violin All of the above None 10. 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 space between the sun and the earth is void The sound so generated is absorbed by various layers of the sun The sun is very far away The sound so generated dissipates away None 11. An astronaut can not hear his companion's sound at the surface of moon because: sound wave does not propagate through vaccum temperature is too low during night and high during day produced frequencies are above the audio frequency none of the above None 12. 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) - (r), (ii) - (q), (iii) - (s), (iv) - (p) (i) - (p), (ii) - (s), (iii) - (r), (iv) - (q) (i) - (p), (ii) - (r), (iii) - (s), (iv) - (q) (i) - (q), (ii) - (p), (iii) - (s), (iv) - (r) None 13. Which of the following vibrating parts of instrument is not matched with the respective instrument None of the above Drum- Stretched Membrane Mridangam - Stretched Membrane Tabla - Stretched Membrane None 14. Sound waves having the following frequency are audible to human beings: 5000 cycles/sec 27000 cycles/sec 5 cycles/sec 50,000 cycles/sec None 15. The maximum displacement of a particle in a vibratory motion is known as Time period frequency Wavelength Amplitude 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.
