Class 9 Science MCQ Sound

Question :For hearing a distinct sound, the time interval between the original sound and the reflected one must be at least:
(a) 1 s
(b) 0.1 s
(c) 2 s
(d) 0.2 s

Question :The persistence of sound in an auditorium is the result of repeated reflections of sound and is called:
(a) reverberation
(b) audible
(c) distinct sound
(d) reflection

Question :The speed v, frequency υ, and wavelength λ, of sound are related by the equation:
(a) v = λυ
(b) υ = λv
(c) λ = υv
(d) v = $\frac{\lambda}{υ}$

Question :The speed of sound is maximum in:
(a) solids
(b) liquids
(c) gases
(d) All of these

Question :Our ears are sensitive to sound frequencies between:
(a) 20 Hz to 20 kHz
(b) 2 Hz to 20 Hz
(c) 20 kHz to 200 kHz
(d) 2000 kHz to 20000 kHz

Question :Which of the following waves are produced by bats?
(a) Infrasonic waves
(b) Ultrasonic waves
(c) Audible waves
(d) All of these

Question :Maximum tolerable sound is:
(a) 0 dB
(b) 10 dB
(c) 60 dB
(d) 120 dB

Question :Sound waves are:
(a) magnetic waves
(b) electric waves
(c) electromagnetic waves
(d) mechanical waves

Question :In SONAR, we use:
(a) ultrasonic waves
(b) infrasonic waves
(c) radio waves
(d) audible sound waves

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

Question :When we change feeble sound to loud sound we increase its:
(a) frequency
(b) amplitude
(c) velocity
(d) wavelength

Question :In the curve half the wavelength is:

Question :An earthquake produces which kind of sound before the mainshock wave begins:
(a) ultrasound
(b) infrasound
(c) audible sound
(d) None of the above

Question :Infrasound can be heard by:
(a) dog
(b) bat
(c) rhinoceros
(d) human beings

Question : The speed v, frequency υ, and wavelength λ, of sound are related by the equation:
(a) v = λυ
(b) υ = λv
(c) λ = υv
(d) v = λ\υ

Question : On increasing the temperature, the speed of sound in air:
(a) Increases
(b) Decreases
(c) Does not change
(d) First increases then becomes constant

Question : Note is a sound
(a) of mixture of several frequencies
(b) of mixture of two frequencies only
(c) of a single frequency
(d) always unpleasant to listen

Question : The upper frequency limit of the audible range of human hearing is about
(a) 20 kHz
(b) 2000 Hz
(c) 2 kHz
(d) 2,000,000 Hz

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

Question : The speed of sound is maximum in:
(a) solids
(b) liquids
(c) gases
(d) All of these

Question : Which of the following can produce longitudinal as well as transverse waves under different conditions?
(a) Bats
(b) Slinky
(c) Tuning fork
(d) None of these

Question : In SONAR, we use
(a) ultrasonic waves
(b) infrasonic waves
(c) radio waves
(d) audible sound waves

Question : Sound wave is a
(a) transverse wave
(b) longitudinal wave
(c) both a and b
(d) None of these

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

Question : Maximum tolerable sound is:
(a) 0 dB
(b) 10 dB
(c) 60 dB
(d) 120 dB

Question : 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

Question : When we change feeble sound to loud sound we increase its
(a) frequency
(b) amplitude
(c) velocity
(d) wavelength

Question : Sound travels
(a) slower in warm air than in cold air
(b) faster in solids and liquids than in air
(c) slower in water than air
(d) none of these

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

Question : An earthquake produces which kind of sound before the mainshock wave begins:
(a) ultrasound
(b) infrasound
(c) audible sound
(d) None of the above

Question : Earthquake produces which kind of sound before the main shock wave begins
(a) ultrasound
(b) infrasound
(c) audible sound
(d) none of the above

Question : Sound can travel through
(a) gases only
(b) vacuum only
(c) gases and liquids only
(d) solids, liquids and gases.

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

Question : The transfer of energy in a material medium due to the periodic motion of its particles is called:
(a) Wave front
(b) Wave motion
(c) Pulse
(d) None of the above

Question :The velocity of sound in air at 30°C is approximately–
(a) 332 ms^–1
(b) 350 ms^–1
(c) 530 ms^–1
(d) 332 kms^–1

Question : With the rise of temperature, the velocity of sound–
(a) Decreases
(b) Increases
(c) Remains the same
(d) Is independent of temperature

Question : What is the name of short duration wave–
(a) Pulse
(b) Frequency
(c) Time period
(d) Velocity

Question : What is the velocity of sound in water at room temperature–
(a) 1500 m/s
(b) 330 m/s
(c) 1500 km/s
(d) 330 km/s