Class 8 Science

Sound

Extra Questions

Multiple Choice Questions

Question 1: Sound usually travels through which medium to reach our ears?

  • Air
  • Water
  • Wood
  • Asbestos

Answer: (a) Air

Question 2: What is the speed of sound in air?

  • 110 m/s
  • 220 m/s
  • 330 m/s
  • 440 m/s

Answer: (c) 330 m/s


Question 3: What is the loudness of normal breathing?

  • 10 dB
  • 20 dB
  • 30 dB
  • 40 dB

Answer: (a) 10 dB

Question 4: What is the length of vocal cords in men?

  • 5 mm
  • 10 mm
  • 15 mm
  • 20 mm

Answer: (d) 20 mm


Question 5: What is the length of vocal cords in women?

  • 5 mm
  • 10 mm
  • 15 mm
  • 20 mm

Answer: (c) 15 mm

Question 6: A vibrating body should oscillate minimum how many times per second to make an audible sound for humans?

  • 10 times
  • 20 times
  • 30 times
  • 40 times

Answer: (b) 20 times

Question 7: Which of the following produces noise only?

  • Jet engine
  • Harmonium
  • Flute
  • Guitar

Answer: (a) Jet engine


Very Short Answer Type Questions

Question 1: What is sound?

Answer: Sound is a kind of wave which gives us sense of hearing.

Question 2: What is vibration?

Answer: The to and fro or back and forth motion of an object is called vibration.

Question 3: Humans produce voice from which organ?

Answer: Voice box

Question 4: What do you understand by frequency of a vibration?

Answer: Number of oscillations per second is called frequency of oscillation.

Question 5: What do you understand by amplitude?

Answer: Maximum displacement of a wave from mean position is called amplitude.

Question 6: Which type of sound is called music?

Answer: A sound which is pleasant to ears is called music.

Question 7: Which type of sound is called noise?

Answer: Any unpleasant sound is called noise.