Online Test — Sound
25 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 25
Sound is always produced by an object that is:
Heated
Vibrating
Stretched
Charged
Explanation: Every sound originates from a vibrating object; stopping the vibration stops the sound.
Question 2 of 25
Sound waves are classified as:
Transverse waves
Longitudinal waves
Light waves
Surface waves
Explanation: In sound, particles vibrate in the same direction as the wave travels, making it longitudinal.
Question 3 of 25
Sound cannot travel through:
A solid
A liquid
A gas
A vacuum
Explanation: A vacuum has no particles to carry the vibration, so sound cannot travel through it.
Question 4 of 25
A region in a sound wave where the medium's particles are pushed close together is a:
Rarefaction
Compression
Reflection
Refraction
Explanation: A compression is a region of crowded particles and higher pressure in a sound wave.
Question 5 of 25
The bell-jar experiment, in which a bell becomes silent as air is removed, proves that sound:
Travels faster in air
Needs a material medium
Is a transverse wave
Cannot be reflected
Explanation: The fading bell shows sound needs a medium and cannot travel through a vacuum.
Question 6 of 25
The loudness of a sound depends mainly on the wave's:
Frequency
Amplitude
Quality
Speed
Explanation: Loudness increases with amplitude; a larger amplitude gives a louder sound.
Question 7 of 25
The pitch of a sound is determined by its:
Amplitude
Frequency
Loudness
Timbre
Explanation: Pitch depends on frequency — a higher frequency gives a higher pitch.
Question 8 of 25
The number of vibrations made in one second is the frequency, measured in:
Decibels
Joules
Hertz
Metres
Explanation: Frequency is measured in hertz (Hz), the number of vibrations per second.
Question 9 of 25
The characteristic that lets us tell a flute from a guitar playing the same note is:
Loudness
Pitch
Quality (timbre)
Amplitude
Explanation: Quality (timbre) distinguishes sounds of the same pitch and loudness from different sources.
Question 10 of 25
If a vibrating body has a frequency of 25 Hz, its time period is:
25 s
0.04 s
2.5 s
50 s
Explanation: Time period is the reciprocal of frequency: 1 ÷ 25 = 0.04 second.
Question 11 of 25
Sound travels fastest through which type of material?
Gases
Liquids
Solids
Vacuum
Explanation: Tightly packed particles in solids pass vibrations fastest, so sound is fastest in solids.
Question 12 of 25
The approximate audible range of frequencies for humans is:
0 – 20 Hz
20 – 20,000 Hz
20,000 – 40,000 Hz
1 – 10 Hz
Explanation: The normal human ear hears sounds between about 20 Hz and 20,000 Hz.
Question 13 of 25
Sound of frequency above 20,000 Hz is called:
Infrasound
Audible sound
Ultrasound
Echo
Explanation: Frequencies above 20,000 Hz are ultrasound, heard by bats and dolphins.
Question 14 of 25
We see lightning before hearing thunder because:
Sound is faster than light
Light is faster than sound
Thunder comes first
Light needs no medium only
Explanation: Light travels far faster than sound, so the flash reaches us before the thunder.
Question 15 of 25
A ship measures the depth of the sea using ultrasound through a technique called:
Radar
SONAR
Ultrasonography
Echo-writing
Explanation: SONAR sends ultrasound and times its echo from the seabed to find the depth.
Question 16 of 25
A distinct repetition of a sound heard after reflection from a far surface is called:
Reverberation
An echo
A vibration
A compression
Explanation: An echo is a separate, clearly heard repetition of a sound caused by reflection.
Question 17 of 25
For an echo to be heard separately, the reflected sound must return after at least:
0.01 s
0.1 s
1 s
10 s
Explanation: The brain separates two sounds only if they are at least 0.1 second apart.
Question 18 of 25
Sound is reflected best by surfaces that are:
Soft and rough
Hard and smooth
Porous and woolly
Curtained
Explanation: Hard, smooth surfaces reflect sound well, while soft, rough surfaces absorb it.
Question 19 of 25
The lingering of sound due to repeated overlapping reflections in a hall is called:
Echo
Reverberation
Refraction
Resonance
Explanation: Reverberation is the persistence of sound caused by many overlapping reflections.
Question 20 of 25
Reverberation in a cinema hall is reduced by covering the walls with:
Polished metal
Glass sheets
Sound-absorbing materials
Smooth tiles
Explanation: Soft, sound-absorbing materials soak up sound and reduce reverberation.
Question 21 of 25
A pleasant sound produced by regular vibrations is called a:
Noise
Musical sound
Echo
Reverberation
Explanation: A musical sound comes from regular vibrations and is pleasant to hear.
Question 22 of 25
The presence of excessive or unwanted sound in the environment is called:
Air pollution
Noise pollution
Water pollution
Light pollution
Explanation: Noise pollution is the presence of too much unwanted sound in surroundings.
Question 23 of 25
Which of the following is a major source of noise pollution?
Whispering
A flowing stream
Vehicle horns
Rustling leaves
Explanation: Vehicle horns and engines are a major source of city noise pollution.
Question 24 of 25
Continuous exposure to loud noise can cause:
Better hearing
Hearing loss and stress
Improved sleep
Lower blood pressure
Explanation: Loud prolonged noise can damage hearing and cause stress, headaches, and high blood pressure.
Question 25 of 25
Planting trees along roadsides helps control noise pollution because trees:
Reflect all sound
Absorb and scatter sound
Produce louder sounds
Increase echoes
Explanation: Trees absorb and scatter sound, reducing the noise that reaches nearby homes.