Class 8 Science
Multiple Choice Questions
Question 1: Sound usually travels through which medium to reach our ears?
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?
Answer: (a) 10 dB
Question 4: What is the length of vocal cords in men?
Answer: (d) 20 mm
Question 5: What is the length of vocal cords in women?
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
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.