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.
Sound
Chapter – 12
Multiple Choice Questions & Answers
1. Sound can not travel through –
(a) air
(b) water
(c) steel
(d) vacuum
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 –
(a) trough
(b) crest
(c) wavelength
(d) frequency
Ans: (b) crest.
4. A valley is called the –
(a) frough
(b) crest
(c) wavelength
(d) frequency
Ans: (a) frough.
5. What is the S. I. unit of frequency?
(a) Hz
(b) Second
(c) metre
(d) S
Ans: (a) Hz.
6. What is S. I. unit wavelength?
(a) Hz
(b) second
(c) metre
(d) fout
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?
(a) 700m/s
(b) 70m/s
(c) 7m/s
(d) 0.7m/s
Ans: (a) 700m/s.
9. At 0.c, the speed of sound in air is –
(a) 330ms⁻¹
(b) 331ms⁻¹
(c) 334ms⁻¹
(d) 344ˢ⁻¹
Ans: (b) 331ms⁻¹
10. At 22°c, the speed of sound in air is
(a) 330ms⁻¹
(b) 331ms⁻¹
(c) 334ms⁻¹
(d) 344ms⁻¹
Ans: (d) 344ms⁻¹
11. At 25°c, the speed of sound in is water –
(a) 4700ms⁻¹
(b) 3980ms⁻¹
(c) 1531ms⁻¹
(d) 1498ms⁻¹
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?
(a) frumpets
(b) shehanais
(c) horms
(d) stethocope
Ans: (d) Stethocope.
15. Which of the following is medical instrument?
(a) Stethoscope
(b) hornes
(c) trumpets
(d) shehanais
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?
(a) 1Hz=4cycle/s
(b) 1Hz=3cycles
(c) 1Hz=2cycle/s
(d) 1Hz=1cycle/s
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 –
(a) 7Hz
(b) 6Hz
(c) 5Hz
(d) 4Hz
Ans: (c) 5Hz.
20. Which of the following can hear high frequency squeaks of the bat?
(a) rat
(b) ant
(c) moth
(d) lizard
Ans: (c) moth
21. Infrasound can be produced by –
(a) whales
(b) dolphins
(c) bats
(d) porpoise
Ans: (a) whales.
22. Which of the following animal play games by producing ultrasound?
(a) dolphine
(b) elephant
(c) bats
(d) rats
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.
Ans: Sound.
3. What is the most common medium through which sound travels?
Ans: air.
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.
Ans: light.
13. Give an example of wave which is not mechanical wave?
Ans: light.
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?
Ans: metre.
16. What is the Symbol of wavelength?
Ans:
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?
Ans: Second.
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?
1
Ans: v= ——
T
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?
Ans: Megaphones.
29. Write the name of an instrument which is used for listening sound of lungs and heartbeat.
Ans: Stethoscope.
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.
