Class 9 Science MCQ Chapter 12 Sound, Class 9 Science MCQ Question Answer, Class 9 Science Multiple Choice Question Answer to each chapter is provided in the list of SCERT Science Class 9 Objective Types Question Answer so that you can easily browse through different chapters and select needs one. Class 9 Science MCQ Chapter 12 Sound Question Answer can be of great value to excel in the examination.
SCERT Class 9 Science MCQ Chapter 12 Sound
SCERT Class 9 Science MCQ Chapter 12 Sound Notes covers all the exercise questions in SCERT Science Textbooks. The NCERT Class 9 Science MCQ Chapter 12 Sound provided here ensures a smooth and easy understanding of all the concepts. Understand the concepts behind every chapter and score well in the board exams.
Chapter – 12
Multiple Choice Questions & Answers
1. Sound can not travel through –
Ans: (d) vacuum.
2. Sound is a –
(a) potential wave
(b) kinetic wave
(c) mechanical wave
(d) none of the above
Ans: (c) mechanical wave.
3. A peak is called –
Ans: (b) crest.
4. A valley is called the –
Ans: (a) frough.
5. What is the S. I. unit of frequency?
Ans: (a) Hz.
6. What is S. I. unit wavelength?
Ans: (c) metre.
7. Which of the following is correct?
(a) wavelength = speed × frequency
(b) speed = wavelength × frequency
(c) frequency = speed × wavelength
(d) none of the above
Ans (b) speed wavelength × frequency.
8. A sound wave has a frequency of 2000 Hz and wave length 0.35 metre. What is the speed of sound wave?
Ans: (a) 700m/s.
9. At 0.c, the speed of sound in air is –
Ans: (b) 331ms⁻¹
10. At 22°c, the speed of sound in air is
Ans: (d) 344ms⁻¹
11. At 25°c, the speed of sound in is water –
Ans: (c) 1531ms⁻¹
12. The sensation of sound persists in our brain for about-
(a) 0.1 second
(b) 0.2 second
(c) 0.3 second
(d) 0.4 second
Ans: (a) 0.1 second.
13. The minimum distance for hearing dis. tinct echos from the source is –
(a) 17.0 m
(b) 17.2 m
(c) 17.3 m
(d) 17.4 m
Ans: (b) 17.2 m
14. Which of the following is not musical instrument?
Ans: (d) Stethocope.
15. Which of the following is medical instrument?
Ans: (a) Stethoscope.
16. The audible range of sound for human beings extends from about
(a) 10Hz to 2000Hz
(b) 20Hz to 20000Hz
(c) 10Hz to 2000Hz
(d) 20Hz to 2000Hz
Ans: (b) 20Hz to 20000Hz
17. Which of the following is correct?
Ans: (d) 1Hz-1cycle/s.
18. Which of following animal can hear a sound of the frequency upto 25000Hz?
(a) above 18 years old man
(b) above 14 years old
(c) above the age of 7 years old children
(d) under the age of 5 years children
Ans: (d) under the age of 5 years children.
19. Rhinoceroces communicate using infrasound of frequency as low as –
Ans: (c) 5Hz.
20. Which of the following can hear high frequency squeaks of the bat?
Ans: (c) moth
21. Infrasound can be produced by –
Ans: (a) whales.
22. Which of the following animal play games by producing ultrasound?
Ans: (d) rats.
Very Short Answer Type Questions
1. What is called medium?
Ans: The matter or substance through which sound is transmitted is called medium.
2. Give an example of wave.
3. What is the most common medium through which sound travels?
4. What is called crest of wave?
Ans: A peak is called crest of wave?
5. What is called trough of a wave?
Ans: A valley is called the trough of wave.
6. What do you mean by compression?
Ans: The maximum pressure in a area is called compresion.
7. What do you mean by rarefactions?
Ans: The minimum pressure in a area is called rarefaction.
8. What is sound wave?
Ans: Sound is a mechanical wave.
9. What is called longitudinal wave?
Ans: The individual particles of the medium move in a direction parallel to the direction of propagation of the disturbance. It is called longitudinal wave.
10. Give an example of longitudinal wave?
Ans: Sound wave.
11. What is called transverse wave?
Ans: Particles up and down about their mean position as the wave trakets. This wave is called transverse wave.
12. Give an example of transverse wave.
13. Give an example of wave which is not mechanical wave?
14. What is called wavelength?
Ans: The distance between two consecutive compressions or two consecutive rarefactions is called the wavelength.
15. What is the S. I. unit of wavelength?
16. What is the Symbol of wavelength?
17. What is called time period?
Ans: The time taken for one complete Oscillation in the density of the medium is called the time period.
18. What is the S.I. unit of time period?
19. What is the S.I. unit of frequency?
Ans: Hz (Hertz)
20. Time period (T) and frequency (v), What is the relation between them?
Ans: v= ——
21. What is called pitch?
Ans: The brain interprets the frequency of an emitted sound is called pitch.
22. What is called amplitude of the wave?
Ans: The magnitude of the maximum disturbance in the medium on the either side of the mean value is called the amplitude of the wave.
23. What is called tone?
Ans: A sound of single frequency is called a tone.
24. What is called note?
Ans: The sound which is produced due to a mixture of several frequencies is called note.
25. What is the difference between note and noise?
Ans: Note is pleasant to listen to and noise is unpleasant to ear.
26. What is th speed of sound at 25°c is Oxygen?
Ans: 316 ms⁻¹
27. What is called echo?
Ans: Shout or clap a suitable reflecting object such as a tall building or a mountain, after a little time, the sound can hear again. It is called echo.
28. Write the name of an instrument which is used multiple reflection of sound?
29. Write the name of an instrument which is used for listening sound of lungs and heartbeat.
30. What is called ultrasonic sound?
Ans: Frequencies higher than 20KHz are called ultrasonic sound or ultra sound.
31. What is called infrasonic sound?
Ans: Sound of frequencies below 20 Hz are called infrasonic sound or infrasound.
32. Write the three bones is the ear.
Ans: hammer, anvil and stirrup.
33. What is called pinna?
Ans: The outer ear is called pinna.