Within the broad domain of competitive exams such as UPSC, where knowledge is sought after in a multitude of areas, the combination of science and technology is paramount. Today, in this article Science And Technology For UPSC let's take a tour into the complex realm of acoustics and investigate the amazing realm of sound, a phenomenon that not only permeates our surroundings but also has a significant influence on them.
Science And Technology For UPSC Part-1 SOUND.
- Sound is produced by a Vibrating body.
- Sound needs a medium for propagation.
- It propagates through water, and solid blocks also, The to-and-fro motion of an object is known as vibration [ oscillatory motion].
- The number of oscillations per second is called. frequency of oscillation. "Frequency is expressed in Hertz.
- Loudness of Sound is 20 Herts. proportional to The Square of The amplitude of The Vibration producing the Sound.
- l∝a2
- Above 80 dB the noise becomes physically painful.
- The loudness of Sound depends on its amplitude.
- Frequency determines the pitch of Sound.
- Sound frequency less than about 20Hz cannot be detected by the human ear. - Inaudible.
- Sounds of Frequency higher than about 20,000 Hz are also inaudible to the human ear.
- The human audible range is from 20 to 20kHz
- The ultra Sound equipment, familiar to us for investigating and tracking medical problems works at frequencies higher Than 20,000 Hz.
- Plantations on the roadside and elsewhere can reduce noise pollution.
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MCQS ON SOUND.
What is the primary cause of sound production?
A. Heat
B. Light
C. Vibrating body
D. Static electricity
Answer: C. Vibrating body
Explanation: Sound is primarily produced by the vibration of a body.
In which medium does sound NOT propagate?
A. Air
B. Water
C. Vacuum
D. Solid blocks
Answer: C. Vacuum
Explanation: Sound requires a medium for propagation, and it cannot travel through a vacuum.
What is the unit of frequency?
A. Decibel
B. Watt
C. Hertz
D. Newton
Answer: C. Hertz
Explanation: Frequency is expressed in Hertz.
What property of vibration is loudness proportional to?
A. Frequency
B. Amplitude squared
C. Speed
D. Wavelength
Answer: B. Amplitude squared
Explanation: Loudness is proportional to the square of the amplitude of vibration.
At what decibel level does noise become physically painful?
A. 60 dB
B. 80 dB
C. 100 dB
D. 120 dB
Answer: B. 80 dB
Explanation: Noise becomes physically painful above 80 dB.
What does the loudness of sound depend on?
A. Frequency
B. Amplitude
C. Medium
D. Temperature
Answer: B. Amplitude
Explanation: The loudness of sound depends on its amplitude.
What property of sound determines its pitch?
A. Amplitude
B. Wavelength
C. Frequency
D. Speed
Answer: C. Frequency
Explanation: Frequency determines the pitch of sound.
Sounds with a frequency less than 20 Hz are considered:
A. Audible
B. Inaudible
C. High-pitched
D. Low-pitched
Answer: B. Inaudible
Explanation: Sounds below 20 Hz are inaudible to the human ear.
What is the human audible range of frequency?
A. 1 to 10 Hz
B. 20 to 20,000 Hz
C. 50 to 50,000 Hz
D. 10 to 100 Hz
Answer: B. 20 to 20,000 Hz
Explanation: The human audible range is typically from 20 to 20,000 Hz.
At what frequencies do ultrasonic equipment work?
A. Below 1 Hz
B. 5,000 to 10,000 Hz
C. 20,000 Hz and above
D. 1,000 to 5,000 Hz
Answer: C. 20,000 Hz and above
Explanation: Ultrasonic equipment operates at frequencies higher than 20,000 Hz.
What is a potential solution to reduce noise pollution mentioned in the passage?
A. Increase industrial activities
B. Implementing traffic regulations
C. Plantation on the roadside
D. Constructing taller buildings
Answer: C. Plantation on the roadside
Explanation: Plantation on the roadside is suggested as a means to reduce noise pollution.
What is the primary factor influencing the loudness of sound?
A. Temperature
B. Medium density
C. Frequency
D. Amplitude
Answer: D. Amplitude
Explanation: The loudness of sound is primarily determined by the amplitude of the vibrations.
Which term describes the to-and-fro motion of an object?
A. Vibration
B. Frequency
C. Oscillation
D. Resonance
Answer: A. Vibration
Explanation: The to-and-fro motion of an object is known as vibration or oscillatory motion.
What is the unit of measurement for loudness?
A. Decibel
B. Hertz
C. Watt
D. Newton
Answer: A. Decibel
Explanation: Loudness is measured in decibels (dB).
What is the frequency range of sounds considered as ultrasonic?
A. Below 1 Hz
B. 1,000 to 10,000 Hz
C. 20 to 20,000 Hz
D. Above 20,000 Hz
Answer: D. Above 20,000 Hz
Explanation: Ultrasonic sounds have frequencies higher than 20,000 Hz.
In which medium does sound propagate faster: air or water?
A. Air
B. Water
C. Same speed in both
D. Depends on frequency
Answer: B. Water
Explanation: Sound generally propagates faster in water than in air.
What happens to the pitch of a sound as its frequency increases?
A. Pitch decreases
B. Pitch remains constant
C. Pitch increases
D. Pitch becomes inaudible
Answer: C. Pitch increases
Explanation: Higher frequency corresponds to higher pitch.
Which of the following is an example of an inaudible sound?
A. A whistle
B. A drumbeat
C. Infrasound
D. A trumpet sound
Answer: C. Infrasound
Explanation: Infrasound has frequencies below the audible range.
What property of sound is related to the sensation of volume?
A. Frequency
B. Amplitude
C. Wavelength
D. Pitch
Answer: B. Amplitude
Explanation: Amplitude is linked to the perceived volume of sound.
What is the primary purpose of ultrasonic equipment in the medical field?
A. Generating audible alarms
B. Cleaning medical instruments
C. Imaging and tracking medical problems
D. Enhancing patient comfort
Answer: C. Imaging and tracking medical problems
Explanation: Ultrasonic equipment is commonly used for medical imaging.
How does the human ear respond to frequencies higher than 20,000 Hz?
A. Inaudible
B. Painful
C. No response
D. Pleasurable
Answer: A. Inaudible
Explanation: Human ears cannot detect frequencies higher than 20,000 Hz.
What is the formula for calculating loudness based on amplitude?
A. l∝a
B. l = a
C. l∝a^2
D. l = 2a
Answer: C. l∝a^2
Explanation: Loudness is proportional to the square of the amplitude.
Which of the following is an example of noise pollution mitigation mentioned in the passage?
A. Increasing industrial activities
B. Implementing traffic regulations
C. Constructing taller buildings
D. Plantation on the roadside
Answer: D. Plantation on the roadside
Explanation: Plantation is suggested as a measure to reduce noise pollution.
What is the primary sensation associated with amplitude in sound?
A. Brightness
B. Loudness
C. Color
D. Pitch
Answer: B. Loudness
Explanation: Amplitude is directly related to the perceived loudness of sound.
At what frequency range does human hearing typically become impaired?
A. 5 to 10 Hz
B. 15,000 to 18,000 Hz
C. 20,000 to 25,000 Hz
D. 1 to 2 Hz
Answer: C. 20,000 to 25,000 Hz
Explanation: Frequencies beyond the upper limit of human hearing can impair hearing over time.
Which property of sound determines its quality or timbre?
A. Frequency
B. Amplitude
C. Harmonics
D. Pitch
Answer: C. Harmonics
Explanation: The quality or timbre of sound is influenced by the presence of harmonics.
What happens to the speed of sound as the medium's temperature increases?
A. Speed decreases
B. Speed remains constant
C. Speed increases
D. Depends on the frequency
Answer: C. Speed increases
Explanation: In general, the speed of sound increases with higher temperatures.
Which of the following terms is associated with the bending of sound waves around obstacles?
A. Reflection
B. Refraction
C. Diffraction
D. Absorption
Answer: C. Diffraction
Explanation: Diffraction refers to the bending of waves around obstacles.
What is the primary reason for using solid blocks in sound propagation?
A. Enhanced speed
B. Absence of air
C. Higher amplitude
D. Increased frequency
Answer: B. Absence of air
Explanation: Sound can propagate through solid blocks due to the absence of air.
Which of the following units is used to measure the intensity of sound?
A. Hertz
B. Decibel
C. Newton
D. Watt
Answer: B. Decibel
Explanation: The intensity of sound is measured in decibels (dB).
What term describes the phenomenon of echoes in sound waves?
A. Refraction
B. Reflection
C. Diffraction
D. Absorption
Answer: B. Reflection
Explanation: Echoes result from the reflection of sound waves.
What is the relationship between frequency and wavelength in a sound wave?
A. Directly proportional
B. Inversely proportional
C. No relationship
D. Depends on the amplitude
Answer: B. Inversely proportional
Explanation: Frequency and wavelength are inversely proportional in a sound wave.
Which of the following frequencies is associated with a high-pitched sound?
A. 50 Hz
B. 500 Hz
C. 5,000 Hz
D. 15,000 Hz
Answer: D. 15,000 Hz
Explanation: Higher frequencies are associated with high-pitched sounds.
What type of sound is deliberately produced for therapeutic purposes, known for its calming effect?
A. Infrasound
B. Ultrasound
C. White noise
D. Pink noise
Answer: C. White noise
Explanation: White noise is often used for its calming effect in therapeutic settings.
Which of the following materials would be the best conductor of sound?
A. Wood
B. Rubber
C. Metal
D. Plastic
Answer: C. Metal
Explanation: Metals are generally good conductors of sound.
What is the primary factor determining the speed of sound in a medium?
A. Frequency
B. Amplitude
C. Density
D. Wavelength
Answer: C. Density
Explanation: The speed of sound is influenced by the density of the medium.
Which part of the ear is responsible for transmitting sound vibrations to the brain?
A. Cochlea
B. Eardrum
C. Ossicles
D. Auditory nerve
Answer: D. Auditory nerve
Explanation: The auditory nerve transmits signals to the brain for interpretation.
What phenomenon allows us to hear sound around corners?
A. Reflection
B. Refraction
C. Diffraction
D. Interference
Answer: C. Diffraction
Explanation: Diffraction enables us to hear sound around obstacles.
What is the name of the unit used to measure the pitch of sound?
A. Hertz
B. Decibel
C. Phon
D. Watt
Answer: A. Hertz
Explanation: Pitch is measured in Hertz.
In which scenario would sound travel the fastest?
A. Through air at a low temperature
B. Through air at a high temperature
C. Through water
D. Through a vacuum
Answer: C. Through water
Explanation: Sound generally travels faster through denser mediums, such as water.
What type of sound is often used to mask or cover up other unwanted sounds?
A. Ultrasound
B. White noise
C. Infrasound
D. Echo
Answer: B. White noise
Explanation: White noise is commonly used to mask or cover up unwanted sounds.
Which term describes the phenomenon of a sound wave bouncing back after hitting a surface?
A. Refraction
B. Reflection
C. Diffraction
D. Absorption
Answer: B. Reflection
Explanation: Reflection occurs when a sound wave bounces back after hitting a surface.
What is the primary purpose of the eardrum in the ear?
A. Amplify sound
B. Transmit sound vibrations to the brain
C. Convert sound waves into electrical signals
D. Protect the inner ear
Answer: D. Protect the inner ear
Explanation: The eardrum protects the delicate inner structures of the ear.
Which of the following is an example of a low-frequency sound wave?
A. 500 Hz
B. 5,000 Hz
C. 50 Hz
D. 20,000 Hz
Answer: C. 50 Hz
Explanation: Lower frequencies, such as 50 Hz, are considered low-frequency sounds.
What is the phenomenon where sound waves cancel each other out, resulting in decreased amplitude?
A. Diffraction
B. Refraction
C. Interference
D. Absorption
Answer: C. Interference
Explanation: Interference occurs when sound waves combine, leading to changes in amplitude.
Which part of the ear is responsible for converting sound vibrations into electrical signals?
A. Cochlea
B. Eardrum
C. Ossicles
D. Auditory nerve
Answer: A. Cochlea
Explanation: The cochlea is responsible for converting sound vibrations into electrical signals.
What is the primary purpose of using ultrasound in medical imaging?
A. Producing audible sounds
B. Generating heat
C. Visualizing internal structures
D. Inducing sleep
Answer: C. Visualizing internal structures
Explanation: Ultrasound is commonly used in medical imaging to visualize internal structures.
Which term describes the decrease in sound intensity as it passes through a medium?
A. Reflection
B. Refraction
C. Diffraction
D. Absorption
Answer: D. Absorption
Explanation: Absorption refers to the decrease in sound intensity as it passes through a medium.
What is the approximate speed of sound in air under normal conditions?
A. 343 meters per second
B. 100 meters per second
C. 500 meters per second
D. 700 meters per second
Answer: A. 343 meters per second
Explanation: Under normal conditions, the speed of sound in air is approximately 343 meters per second.
Which of the following is an example of a natural source of infrasound?
A. Thunderstorms
B. Car engines
C. Whistles
D. Music concerts
Answer: A. Thunderstorms
Explanation: Thunderstorms are a natural source of infrasound, producing low-frequency waves.
What is the minimum distance required for a distinct echo to be heard?
A) 10m
B) 17m
C) 20m
D) 30m
Answer: B) 17m
Explanation: The minimum distance for a distinct echo is given as 17m.
How long does the sensation of sound persist in the human ear?
A) 0.01 seconds
B) 0.1 seconds
C) 1 second
D) 10 seconds
Answer: B) 0.1 seconds
Explanation: The sensation of sound persists in the ear for about 0.1 seconds.
What is the speed of sound in the air?
A) 300 m/s
B) 340 m/s
C) 400 m/s
D) 500 m/s
Answer: B) 340 m/s
Explanation: The speed of sound in air is given as 340 m/s.
Which animals can hear ultrasonic sounds?
A) Dogs, cats, and bats
B) Elephants, lions, and giraffes
C) Fish, turtles, and dolphins
D) Humans and monkeys
Answer: A) Dogs, cats, and bats
Explanation: Dogs, cats, and bats are mentioned as animals that can hear ultrasonic sounds.
What is the frequency range for ultrasonic sounds?
A) Less than 20 Hz
B) 20 Hz to 20,000 Hz
C) More than 20,000 Hz
D) 10,000 Hz to 50,000 Hz
Answer: C) More than 20,000 Hz
Explanation: Ultrasonic sounds have frequencies beyond 20,000 Hz.
What can ultrasonic waves be used for in the medical field?
A) Insect repellent
B) Bloodless surgery
C) Traffic control
D) Doppler effect
Answer: B) Bloodless surgery
Explanation: Ultrasonic waves can be used in bloodless surgery.
Which property of atoms can be inferred using ultrasonic waves?
A) Density
B) Color
C) Temperature
D) Hardness
Answer: A) Density
Explanation: Ultrasonic waves can infer physical properties like the density of atoms.
What is the Doppler effect?
A) Change in frequency due to a change in medium
B) Change in wavelength due to a change in velocity
C) Change in velocity, frequency, and wavelength
D) Change in frequency due to the motion of the source or observer
Answer: D) Change in frequency due to the motion of the source or observer
Explanation: The Doppler effect is the change in frequency due to the motion of the source or observer.
What is radar used for?
A) Bloodless surgery
B) Traffic control
C) Insect repellent
D) Ultrasonic imaging
Answer: B) Traffic control
Explanation: Radar is used to track vehicles and enforce speed limits in traffic control.
What type of wave are sound waves characterized as?
A) Transverse wave
B) Infrasonic wave
C) Ultrasonic wave
D) Mechanical wave
Answer: D) Mechanical wave
Explanation: Sound waves are characterized as mechanical waves.
What is compression in a sound wave?
A) Region of low pressure
B) Region of high pressure
C) Region of no pressure
D) Region of maximum disturbance
Answer: B) Region of high pressure
Explanation: Compression is the region of high pressure in a sound wave.
What is the unit of frequency?
A) Newton
B) Joule
C) Hertz
D) Pascal
Answer: C) Hertz
Explanation: Frequency is measured in Hertz (Hz).
What is the wavelength of a sound wave?
A) The distance between two consecutive compressions
B) The distance between two consecutive rarefactions
C) The distance between a compression and a rarefaction
D) The distance traveled by sound in one second
Answer: A) The distance between two consecutive compressions
Explanation: Wavelength is the distance between two consecutive compressions.
What is the term for the magnitude of the maximum disturbance in the medium in a sound wave?
A) Frequency
B) Wavelength
C) Amplitude
D) Velocity
Answer: C) Amplitude
Explanation: The magnitude of the maximum disturbance is called the amplitude.
What is a sound wave of a single frequency called?
A) Ultrasonic wave
B) Infrasonic wave
C) Tone
D) Echo
Answer: C) Tone
Explanation: A sound wave of a single frequency is called a tone.
How is the speed of sound defined?
A) Distance traveled per unit of time
B) Frequency multiplied by wavelength
C) Time period multiplied by velocity
D) Amplitude divided by wavelength
Answer: A) Distance traveled per unit time
Explanation: The speed of sound is defined as the distance traveled per unit time.
What is the term for a sharp and loud sound produced when the speed of an object exceeds the speed of sound?
A) Echo
B) Sonic boom
C) Reverberation
D) Doppler effect
Answer: B) Sonic boom
Explanation: A sonic boom is produced when the speed of an object exceeds the speed of sound.
What causes echoes?
A) Refraction of sound waves
B) Multiple reflections of sound waves
C) Absorption of sound waves
D) Diffraction of sound waves
Answer: B) Multiple reflections of sound waves
Explanation: Echoes are caused by multiple reflections of sound waves.
What is the repeated reflection that results in the persistence of sound called?
A) Doppler effect
B) Echo
C) Sonic boom
D) Reverberation
Answer: D) Reverberation
Explanation: Reverberation is the repeated reflection that results in the persistence of sound.
How does a stethoscope work?
A) By Doppler effect
B) By sonic boom
C) By multiple reflections of sound
D) By reverberation
Answer: C) By multiple reflections of sound
Explanation: A stethoscope works on the principle of multiple reflections of sound.
What is the primary use of radar in traffic control?
A) Bloodless surgery
B) Ultrasonic imaging
C) Tracking vehicles and enforcing speed limits
D) Insect repellent
Answer: C) Tracking vehicles and enforcing speed limits
Explanation: Radar in traffic control is used to track vehicles and enforce speed limits.
Which type of wave do light waves belong to?
A) Transverse wave
B) Infrasonic wave
C) Ultrasonic wave
D) Electromagnetic wave
Answer: D) Electromagnetic wave
Explanation: Light waves belong to the category of electromagnetic waves.
In which region of a sound wave is refraction found?
A) Compression
B) Rarefaction
C) Wavelength
D) Velocity
Answer: B) Rarefaction
Explanation: Refraction is found in the region of rarefaction in a sound wave.
What is the unit of wavelength?
A) Newton
B) Joule
C) Hertz
D) Meter
Answer: D) Meter
Explanation: The unit of wavelength is the meter.
What is the term for the distance between two consecutive rarefactions?
A) Amplitude
B) Wavelength
C) Frequency
D) Velocity
Answer: B) Wavelength
Explanation: Wavelength is the distance between two consecutive rarefactions.
What is the term for the frequency of an emitted sound?
A) Amplitude
B) Pitch
C) Wavelength
D) Velocity
Answer: B) Pitch
Explanation: The frequency of an emitted sound is called pitch.
What can be inferred from the sound waves in terms of physical properties?
A) Color of objects
B) Density of atoms
C) Hardness of materials
D) Temperature of the medium
Answer: B) Density of atoms
Explanation: Sound waves can be used to infer physical properties like the density of atoms.
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