Class 8 Science

Sound

Extra Questions

Multiple Choice Questions

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

  1. Air
  2. Water
  3. Wood
  4. Asbestos

Answer: (a) Air

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

  1. 110 m/s
  2. 220 m/s
  3. 330 m/s
  4. 440 m/s

Answer: (c) 330 m/s

Question 3: What is the loudness of normal breathing?

  1. 10 dB
  2. 20 dB
  3. 30 dB
  4. 40 dB

Answer: (a) 10 dB

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

  1. 5 mm
  2. 10 mm
  3. 15 mm
  4. 20 mm

Answer: (d) 20 mm

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

  1. 5 mm
  2. 10 mm
  3. 15 mm
  4. 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?

  1. 10 times
  2. 20 times
  3. 30 times
  4. 40 times

Answer: (b) 20 times

Question 7: Which of the following produces noise only?

  1. Jet engine
  2. Harmonium
  3. Flute
  4. Guitar

Answer: (a) Jet engine

Very Short Answer Type

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.