MCQ Class 9 Science Chapter 12 Sound

MCQs MCQs Class 9

Please refer to the MCQ Questions for Class 9 Science Chapter 12 Sound. The following Sound Class 9 Science MCQ Questions have been designed based on the latest syllabus and examination pattern for Class 9. Our experts have designed MCQ Questions for Class 9 Science with Answers for all chapters in your NCERT Class 9 Science book.

Sound Class 9 MCQ Questions with Answers

See below Sound Class 9 Science MCQ Questions, solve the questions and compare your answers with the solutions provided below.

Question. Which of the following statement best describes frequency ?   
(a) the maximum disturbance caused by a wave
(b) the number of complete vibrations per second
(c) the distance between one crest of a wave and the next one
(d) the distance travelled by a wave per second

Answer

B

Question. Which of the following vibrates when a musical note is produced by the cymbals in an orchestra ?   
(a) stretched strings
(b) stretched membranes
(c) metal plates
(d) air columns

Answer

C

Question. If the speed of a wave is 340 m/s and its frequency is 1700 Hz, then 􀁏􀀃for this wave in cm will be : 
(a) 2
(b) 0.2
(c) 20
(d) 200

Answer

C

Question. A musical instrument is producing a continuous note. This note cannot be heard by a person having a normal hearing range. This note must then be passing through :   
(a) water
(b) wax
(c) vacuum
(d) empty vessel

Answer

C

Question. Which one of the following does not consist of transverse waves ?   
(a) light emitted by a CFL
(b) TV signals from a satellite
(c) ripples on the surface of a pond
(d) musical notes of an orchestra

Answer

D

Question. Sound travels in air :     
(a) if particles of medium travel from one place to another
(b) if there is no moisture in the atmosphere
(c) if disturbance moves
(d) if both, particles as well as disturbance move from one place to another

Answer

C

Question. The maximum speed of vibrations which produce audible sound will be in :   
(a) dry air
(b) sea water
(c) ground glass
(d) human blood

Answer

C

Question. The sound waves travel fastest :   
(a) in solids
(b) in liquids
(c) in gases
(d) in vacuum

Answer

A

Question. The speeds of sound in four different media are given below. Which of the following is the most likely speed in m/s with which the two under water whales in a sea talk to each other when separated by a large distance ?   
(a) 340
(b) 5170
(c) 1280
(d) 1530

Answer

D

Question. When the pitch of note produced by a harmonium is lowered, then the wavelength of the note :   
(a) decreases
(b) first decreases and then increases
(c) increases
(d) remains the same

Answer

c

Question. The velocities of sound waves in four media P, Q, R and S are 18,000 km/h, 900 km/h, 0 km/h, and 1200 km/h respectively. Which medium could be a liquid substance ? 
(a) P
(b) Q
(c) R
(d) S

Answer

d

Question. Which of the following can produce longitudinal waves as well as transverse waves under different conditions ?   
(a) water
(b) TV transmitter
(c) slinky
(d) tuning fork

Answer

c

Question. Name the type of waves which are used by astronauts to communicate with one another on moon (or in outer space).

Answer

Radio waves

Question. What will be the change in the wavelength of a sound wave in air if its frequency is doubled ?

Answer

Wavelength is halved

Question. Name the device which is used to produce sound in laboratory experiments.

Answer

Tuning fork

Question. What conclusion can be obtained from the observation that when the prongs of a sound making tuning fork touch the surface of water in a beaker, the water gets splashed ?

Answer

That the prongs of tuning fork are vibrating

Question. If 20 waves are produced per second, what is the frequency in hertz ?

Answer

Vacuum

Question. Which of the following cannot transmit sound ?
Water, Vacuum, Aluminium, Oxygen gas

Answer

Vacuum

Question. Which of the following travels slowest in air and which one fastest ?

Answer

Supersonic aircraft, Light, Sound

Question. Which term is used to denote a speed greater than the speed of sound ?

Answer

Supersonic

Question. Name the physical quantity whose SI unit is ‘hertz’.

Answer

Frequency

Question. What type of wave is represented :
(a) by density-distance graph ?
(b) by displacement-distance graph ?

Answer

(a) Longitudinal wave
(b) Transverse wave

Question. What name is given to those aircrafts which fly at speeds greater than the speed of sound ?
Supersonic aircrafts

Answer

Supersonic aircrafts

Question. A jet aircraft flies at a speed of 410 m/s. What is this speed known as ?

Answer

Supersonic speed

Question. Name the two types of waves which can be generated in a long flexible spring (or slinky).

Answer

Transverse waves and Longitudinal waves

Question. A stone is dropped on the surface of water in a pond. Name the type of waves produced.

Answer

Transverse (water) waves

Question. Name the type of waves produced when a tuning fork is struck in air.

Answer

Longitudinal (sound) waves

Question. Which of the following is the speed of sound in copper and which in aluminium ?
(a) 5100 m/s (b) 1500 m/s (c) 3750 m/s

Answer

In copper : 3750 m/s ; In aluminium : 5100 m/s

Question. What is the general name of the waves consisting of :
(a) compressions and rarefactions ?
(b) crests and troughs ?

Answer

(a) Longitudinal waves
(b) Transverse waves

Question. State the general name of the waves in which the particles of the medium vibrate :
(i) in the same direction as wave.
(ii) at right angles to the direction of wave.

Answer

(i) Longitudinal waves
(ii) Transverse waves

Question. What type of waves are illustrated by the movement of a rope whose one end is fixed to a pole and the other end is moved up and down ?

Answer

Transverse waves

Question. What should an object do to produce sound ?

Answer

Vibrate

Question. What is the name of the strings which vibrate in our voice box when we talk ?

Answer

Vocal cords

Question. State whether the following statement is true or false :
Sound produced by a vibrating body travels to our ears by the actual movement of air.

Answer

False

Question. A tuning fork has a number 256 marked on it. What does this number signify ?

Answer

Frequency (of vibration) of the tuning fork

Question. What is the time-period of a tuning fork whose frequency is 200 Hz ?

Answer

5 × 10–3 s

Question. Calculate the frequency of a wave whose time-period is 0.02 s.

Answer

50 Hz

Question. Fill in the following blanks with suitable words :Question The speed of sound in a solid is …………… than the speed of sound in air.

Answer

greater

Question When the frequency of the sound is increased, the wavelength……………..

Answer

decreases

Question Sound is caused by ……………..

Answer

vibrations

Question Wave speed in metres per second equals frequency in ………… multiplied by ………………… in ……………….

Answer

hertz ; wavelength ; metres

Question Sound cannot travel through …………….

Answer

vacuum

Question A sound wave consists of places of higher pressure called …………….. and places of…………….pressure called……………..

Answer

compressions ; lower; rarefactions

Sound Class 9 Science MCQ Questions