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