# CBSE Class 9 Science Important MCQs from Chapter 12 Sound for Annual Exam 2020

Important multiple choice type questions from CBSE Class 9 Physics Chapter 12 - Sound are provided here with answers.

CBSE Class 9 Science Important MCQs from Chapter 12 Sound for Annual Exam 2020

CBSE Class 9th Science question paper in annual exam this year will have one fourth of the questions of objective type.Therefore, students should prepare well for these questions, especially for MCQ questions because most of the questions in Section A of Class 9 Science paper will be of MCQ type.

In this article, you will get the MCQs from Chapter 12 - Sound of CBSE Class 9 Science. All these questions are based on important topics and concepts involved in this chapter. Answers of all questions are also provided here.

Check below the CBSE Class 9 Science important MCQs on Chapter - Sound:

Q1. The sound can travel in air when:

(a) Particles of medium travel from one place to another

(b) There is no moisture in the atmosphere

(c) Disturbance travel from one place to another

(d) Both particles as well as disturbance travel from one place to another

Answer: (c) Disturbance travel from one place to another

Q2. We can distinguish between a man’s voice and a woman’s voice of the same loudness even without seeing them. This is due to a characteristic of sound which measures the shrillness of sounds. Can you choose the correct unit of the quantity on which this characteristic of sound depends?

(a) hertz

(b) meter/second

(c) meter

(d) unitless

Q3. A key of mechanical piano is first struck gently and then struck again but much harder this time. What kind of change in sound will you observe in the second case:

(a) Sound will be louder but the pitch will not be different

(b) Sound will be louder and the pitch will also be higher

(c) Sound will be louder but the pitch will be lower

(d) Both loudness and pitch will remain unaffected

Answer: (c) Sound will be louder but the pitch will be lower

Q4. The echo-receiver of a sonar attached to a ship, receives the echo from the bottom of sea 4 seconds after the ultrasonic waves were sent into the sea.

If the speed of sound in water is 1500 m/s, then what is the depth of the sea?

(a) 6000 m

(b) 3000 m

(c) 15000 m

(d) 3500 m

Answer: (b) 3000 m

Q5. Before the main shock waves, the earthquake produces the characteristic sound waves which some animals like rhinoceros can hear. Can you guess the kind of sound waves produced here?

(a) Infrasonic sounds

(b) Ultrasonic sounds

(c) Audible Sounds

(d) None of these

Answer: (a) Infrasonic sounds

Q6. Given below is the diagram of human ear. Choose the correct labeling of the parts A, B and C.

(a) A-ear lobe, B-ear canal, C-auditory nerve

(b) A-ear drum, B-auditory nerve, c-ear canal

(c) A-ear canal, B-Eustachian tube, C-auditory nerve

(d) A-ear canal, B-Eustachian tube, C-cochlea

Answer: (c) A-ear canal, B-Eustachian tube, C-auditory nerve

Q7. On increasing the temperature, the speed of sound in air:

(a) Increases

(b) Decreases

(c) Does not change

(c) First increases then becomes constant

Q8. Loudness measures the sound energy reaching the ear per second and depends on the amplitude of the sound wave. What is the unit used to measure the loudness of sound?

(a) hertz

(b) decibel

(c) meter/second

(d) second

Q9. We can easily distinguish between the sounds of the different singers even without having seen them. This is all due the different quality or timber of their sounds. On what factor does the quality of sound depend?

(a) Wavelength

(b) Waveform

(c) Wave frequency

(d) Wave amplitude

Q10. Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, he is adjusting

i. Amplitude of the sound

ii. Frequency of the sitar string with the frequency of other musical instruments

iii. Intensity of sound

iii. Loudness of sound

Choose the correct option:

(a) (i) and (iii)

(b) only (ii)

(c) (ii) and (iv)

(d) only (iv)

Answer: (b) only (ii)

Q11. The bats can fly in the darkness of night without colliding with the other objects by emitting special sounds while flying. Which characteristic of sound is used by the bats to navigate?

(a) Ultrasound

(b) Infrasound

(c) Audible sound

(d) None of these

Q12. The sound travels from particle to particle in the form of vibrations and has different speeds in different mediums.

The maximum speed of vibrations which produce audible sound will be in:

(a) Sea water

(b) Ground glass

(c) Human blood

(d) Dry air

Answer: (b) Ground glass

Q13. Which of the following can produce longitudinal as well as transverse waves under different conditions?

(a) Bats

(c) Tuning fork

(d) None of these

Q14. If the speed of a wave is 380 m/s and its frequency is 1900 Hz, then the wavelength of the wave will be:

(a) 20 m

(b) 0.2 m

(c) 200 m

(d) 2 m

Answer: (b) 0.2 m

Q15. You must have seen the doctor checking the sounds produced in the chest or heartbeat of a patient using a medical instrument called Stethoscope. On what principle does this Stethoscope work?

(a) Multiple refractions

(b) Multiple reflections

(c) Wave motion

(d) None of these

Answer: (b) Multiple reflections

Students may also download all the MCQs given above in form of PDF so that they may access these questions in offline mode as well:

MCQs on all the chapters of CBSE Class 9 Science can be checked from the following link:

Also Check:

CBSE Class 9 MCQs for Maths, Science, Social Science & English Exam 2020

CBSE Class 9 Science Important Questions & Answers for Annual Exam 2020

CBSE Class 9 Maths Important Questions & Answers for Annual Exam 2020

Class 9 Science NCERT Book and Solutions PDF

Class 9 Maths NCERT Book and Solutions PDF

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