In which of the following media does sound travel fastest?
- A.Vacuum
- B.Air
- C.Water
- D.Steel
Correct answer
Explanation
The correct answer is D, steel. Sound travels fastest in solids because their particles are packed closely and are strongly bound, so a disturbance is passed on to the next particle almost at once. In steel the speed is about five thousand metres per second, in water about fifteen hundred and in air only about three hundred and forty. The order to remember is solid, then liquid, then gas.
Option A, vacuum, carries no sound at all, since there are no particles to vibrate. Option B, air, is the slowest of the three real media listed because its particles are far apart and take longer to pass the disturbance on. Option C, water, is faster than air but far slower than steel. This is also why a rail track carries the sound of an approaching train long before the sound reaches a listener through the air.
Read the full article: Sound and Waves: Properties, Speed and PYQs
Practice Questions
View allThe frequency of a sound wave is 50 Hz and its wavelength is 4 m. What is the distance travelled by the sound wave in 3 s?
- A.100 m
- B.600 m
- C.200 m
- D.300 m
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The speed of a wave is the product of its frequency and its wavelength, so the speed here is 50 hertz multiplied by 4 metres, that is 200 metres per second.
Read the full explanation →The brain interprets the frequency of an emitted sound called -
- A.Wavelength
- B.Wave velocity
- C.Pitch
- D.Oscillation
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Pitch is the characteristic of a sound by which the brain judges it as shrill or flat, and it is decided by the frequency of the wave.
Read the full explanation →A sound wave has a frequency of 1 kHz and wavelength 50 cm. How long will it take to travel 1 km?
- A.5 s
- B.4 s
- C.3 s
- D.2 s
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Convert the units first: 1 kilohertz is 1000 hertz and 50 centimetres is 0.5 metre. The speed is frequency multiplied by wavelength, that is 1000 multiplied by 0.5, which gives 500 metres per second.
Read the full explanation →The loudness of sound depends upon the
- A.velocity of sound waves in the medium.
- B.amplitude of the sound waves.
- C.frequency of the sound waves.
- D.frequency and velocity of the sound waves.
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Amplitude is the maximum displacement of a particle of the medium from its rest position, and the energy carried by a wave increases with the square of the amplitude.
Read the full explanation →The flash of lightning is seen before the thunderstorm is heard. It verifies that
- A.sound travels much faster than light
- B.light travels much faster than sound
- C.light and sound both travel with same speed
- D.intensity of flash of lightning is very high during thunderstorm
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The flash and the clap are produced at the same instant by the same discharge.
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