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Wednesday, June 10, 2015

Class 8 science test from Sound

Science Class 8 Test Paper  From Sound
Marks:        56 1/2                                                                                                                                                             Time: 1 hour
Answer according to the marks of the question:

Q 1: How is sound produced?                                                                                                                                             (1 mark)

Q 2: Which part of sitar produces sound?                                                                                                                      (1 mark)

Q 3: In humans, when is sound produced?                                                                                                                   (1 mark)

Q 4: Which part of a drum helps in making sound?                                                                                                   (1 mark)

Q 5: What is larynx in human beings?                                                                                                                             (1 mark)

Q 6: How much long the vocal cords of a man are?                                                                                                   (1 mark)

Q 7: What is the length of vocal cords of women?                                                                                                    (1 mark)

Q 8: Write the mediums in which the sound travels.                                                                          (1 and a half mark)

Q 9: Can sound travel through vacuum? Why?                                                                                                          (2 marks)

Q 10: How do dolphins and whales communicate in water?                                                                                 (1 mark)

Q 11: Can sound travel through a gas? Give one example in support.                                                            (2 marks)

Q 12: Why sound cannot be heard on the surface of moon?                                                                                 (1 mark)

Q 13: How much is the speed of sound in air?                                                                                                             (1 mark)

Q 14: Out of solids, liquids and gases in which medium the sound travels fastest and in which slowest? 
(2 marks)

Q 15: What is the speed of light in air?                                                                                                                           (1 mark)

Q 16: Why do we see the flash of lightning first and then hear thunder later?                                           (2 marks)

Q 17: When we put our ear to a railway line, we can hear the sound of an approaching train even when the train is far off but its sound cannot be heard through air. Why?                                                                        (2 marks)

Q 18: Why we should not put anything like pin, pencil pr pen etc. inside our ears?                                  (1 mark)

Q 19: What is amplitude?                                                                                                                                                     (1 mark)
Q 20: Define vibration.                                                                                                                                                           (1 mark)

Q 21: What is time period?  What is its unit?                                                                                                               (1 mark)

Q 22: What is frequency and what is its unit? (1 mark)

Q 23: A pendulum makes 15 oscillations in 5 seconds. What is the frequency of the pendulum? (2 marks)

Q 24: What is the time-period of a pendulum which is vibrating with a frequency of 10 hertz? (2 marks)

Q 25: Greater the ___________, louder the sound will be.                                                                                     (1 mark)

Q 26: What is the relation between loudness and amplitude (in terms of formula).                                 (1 mark)

Q 27: What is the unit for loudness of sound?                                                                                                            (1 mark)

Q 28: How much is the loudness of sound produced by a very noisy factory?                                               (1 mark)

Q 39: What is pitch of a sound?                                                                                                                                          (1 mark)

Q 40: Above what sound level, sound hurts too much?                                                                                          (1 mark)

Q 41: A bird say a crow makes a _____ pitched sound whereas a lion makes a ______ pitched sound. 
(2 marks)

Q 42: Define quality of a sound.                                                                                                                                        (1 mark)

Q 43: What are infrasonics and ultrasonics?                                                                                                               (2 marks)

Q 44: Write two uses of ultrasound.                                                                                                                              (2 marks)

Q 45: Define noise and music.                                                                                                                                          (2 marks)

Q 46: Write one example each of stringed musical instrument, wind musical instrument, membrane type musical instrument and plate type musical instrument.                                                                                      (4 marks)

Q 47: What is noise pollution and two sources of it?                                                                                              (3 marks)

Q 48: Write three measures to control noise pollution.                                                                                        (3 marks)