Every question from this NCERT chapter, with a detailed explanation.
Consider the following statements regarding the propagation of sound: 1. The disturbance created by a source travels through the medium to the listener. 2. Sound waves are characterized as non-mechanical waves. 3. A material medium is mandatory for the transmission of sound. Which of the statements given above are correct?
With reference to the characteristics of a sound wave, consider the following statements: 1. The distance between two consecutive compressions is called the wavelength. 2. The time taken for one complete oscillation is called the frequency. 3. The SI unit of frequency is Hertz. Which of the statements given above are correct?
Consider the following statements regarding Ultrasound: 1. It refers to sounds with frequencies higher than 20 kHz. 2. Ultrasound waves scatter immediately when they encounter obstacles. 3. Ultrasound is incapable of penetrating metal blocks to detect flaws. Which of the statements given above is/are correct?
The cleaning action of an ultrasonic cleaner is primarily achieved through:
With reference to medical applications of sound, consider the following statements: 1. Echocardiography uses ultrasonic waves to form an image of the heart. 2. Ultrasonography uses X-rays to detect stones in the gall bladder. 3. Ultrasound can be used to break kidney stones into fine grains. Which of the statements given above are correct?
Which of the following best explains the working of a Hearing Aid?
Consider the following statements about the speed of sound: 1. The speed of sound is independent of the nature of the medium. 2. It is generally higher in solids than in liquids. 3. It is generally higher in liquids than in gases. Which of the statements given above are correct?
Which one of the following adaptations allows certain moth families to escape predation by bats?
Consider the following statements about the propagation of sound in a slinky: 1. It can demonstrate longitudinal waves. 2. The regions where coils are closer are called rarefactions. 3. The regions where coils are further apart are called compressions. Which of the statements given above is/are correct?
Consider the following statements regarding the speed of sound in different media at 25°C: 1. Speed of sound in Aluminium is lower than in Steel. 2. Speed of sound in Hydrogen is higher than in Air. 3. Speed of sound in Seawater is higher than in Distilled water. Which of the statements given above are correct?
Consider the following statements regarding the use of Ultrasound in industry: 1. It is used to clean spiral tubes and electronic components. 2. It cannot be used to detect cracks in metal blocks. 3. It is used to drill holes in steel plates. Which of the statements given above are correct?
With reference to the audible range of sound, consider the following statements: 1. The audible range for an average human is 200 Hz to 200,000 Hz. 2. Sounds with frequencies below 20 Hz are called infrasound. 3. Rhinoceroses communicate using infrasound. Which of the statements given above are correct?
Which of the following animals is known to produce sound in the infrasound range?
Match List I with List II and select the correct answer using the code given below: List I | List II A. Frequency | 1. Hertz (Hz) B. Wavelength | 2. Second (s) C. Time Period | 3. Metre (m) D. Speed | 4. Metre per second (m/s)
Which of the following statements is correct regarding the propagation of sound in a medium?
Which of the following best explains the time lag between seeing a lightning flash and hearing the thunder?
Match List I with List II and select the correct answer using the code given below: List I | List II A. Crest | 1. Peak of the wave curve B. Trough | 2. Valley of the wave curve C. Compression | 3. Region of high pressure D. Rarefaction | 4. Region of low pressure
With reference to the production of sound, consider the following statements: 1. Sound is a form of energy that produces a sensation of hearing. 2. It is possible to produce sound without the utilization of any energy. 3. Vibration refers to the unidirectional motion of an object. Which of the statements given above is/are correct?
Which one of the following best explains why sound waves are called "mechanical waves"?
With reference to the propagation of sound in air, consider the following statements: 1. A compression is a region of low pressure and low density. 2. A rarefaction is a region of low pressure and low density. 3. Sound propagates as density variations or pressure variations in the medium. Which of the statements given above are correct?
In the context of sound waves, what does the term 'Compression' represent?
Consider the following statements regarding the nature of sound waves: 1. Sound waves in air are longitudinal waves. 2. In a longitudinal wave, particles move perpendicular to the direction of wave propagation. 3. Light waves are examples of longitudinal waves. Which of the statements given above is/are correct?
Which of the following correctly describes the motion of particles in a transverse wave?
Which one of the following physical quantities is determined by the amplitude of a sound wave?
Consider the following statements regarding the 'Pitch' of a sound: 1. Pitch is determined solely by the amplitude of the emitted sound. 2. A high pitch sound corresponds to a higher number of compressions passing a fixed point per unit time. 3. Faster vibration of the source results in a higher pitch. Which of the statements given above are correct?
With reference to the 'Quality' or 'Timbre' of sound, consider the following statements: 1. It enables us to distinguish one sound from another having the same pitch and loudness. 2. A sound of a single frequency is called a note. 3. A sound produced by a mixture of several frequencies is called a tone. Which of the statements given above is/are correct?
Which of the following best describes 'Intensity' of sound?
Consider the following statements regarding the speed of sound: 1. The speed of sound depends on the temperature of the medium. 2. The speed of sound increases when we go from solid to gaseous state. 3. In any medium, as we increase the temperature, the speed of sound increases. Which of the statements given above are correct?
Based on the properties of sound transmission, in which of the following media would sound travel the fastest at a given temperature?
With reference to the reflection of sound, consider the following statements: 1. Sound does not follow the laws of reflection that apply to light. 2. Reflection of sound occurs when sound waves strike the surface of a solid or liquid. 3. The directions of incident and reflected sound make equal angles with the normal. Which of the statements given above are correct?
To distinguish a reflected sound (echo) from the original sound, the minimum time interval between the two must be:
Consider the following statements regarding 'Reverberation': 1. It is the persistence of sound in a big hall due to repeated reflection. 2. Excessive reverberation is highly desirable in concert halls to enhance sound quality. 3. Sound-reflecting materials like glass are used to reduce reverberation. Which of the statements given above is/are correct?
Which of the following devices work on the principle of multiple reflection of sound? 1. Megaphone 2. Microphone 3. Shehanai Select the correct answer using the code given below:
Which one of the following statements is NOT correct regarding sound waves?
In the context of sound, what is a 'Tone'?
Consider the following statements regarding the reflection of sound: 1. The rolling of thunder is due to successive reflections of sound from clouds and land. 2. To reduce reverberation, the roof and walls of an auditorium are covered with sound-reflecting materials. Which of the statements given above is/are correct?
Which of the following pairs is correctly matched? 1. Infrasound : Frequency < 20 Hz 2. Ultrasound : Frequency > 20 kHz 3. Audible Range : 20 Hz – 2000 Hz Select the correct answer using the code given below:
Ordinary sound waves are unsuitable for detecting flaws in metal blocks primarily because:
Which of the following statements best explains why a sound wave is called a longitudinal wave?
With reference to the graphical representation of a sound wave, what does the 'Crest' represent?
Consider the following statements regarding the amplitude of a sound wave: 1. It is the magnitude of the maximum disturbance in the medium on either side of the mean value. 2. As a sound wave moves away from the source, its amplitude increases. 3. Louder sound is associated with higher energy and larger amplitude. Which of the statements given above are correct?
Which of the following factors primarily determines the 'Loudness' of a sound?
"A violin and a flute may be played at the same time... but the sounds we receive are different." This difference is primarily due to which characteristic of sound?
Which of the following statements is correct regarding the relationship between frequency and pitch?
Consider the following statements about 'Note' and 'Noise': 1. A note is a sound that is pleasant to listen to. 2. Noise is produced by a mixture of several frequencies that is unpleasant to the ear. 3. A note is produced by a single frequency. Which of the statements given above is/are correct?
With reference to the reflection of sound, what is the condition for hearing a distinct echo?
Which of the following is used to reduce reverberation in an auditorium?
Consider the following statements regarding the medical use of Ultrasound: 1. It is used in 'echocardiography' to image the heart. 2. It is used in 'ultrasonography' to correct vision defects. 3. It relies on the reflection of waves from regions of changing tissue density. Which of the statements given above are correct?
Which of the following phenomena is responsible for the working of a Stethoscope?
Which of the following phenomena is primarily responsible for the 'rolling' effect of thunder?
Consider the following statements about Infrasound: 1. Infrasound has a frequency higher than 20,000 Hz. 2. It is produced by earthquakes before the main shock waves. 3. Rhinoceroses can communicate using infrasound. Which of the statements given above are correct?
Which of the following correctly describes the relationship between the density of a medium and the pressure in a sound wave?
With reference to the speed of sound, which of the following statements is correct?
Which of the following is a practical application of the reflection of sound?
Consider the following statements regarding the 'Time Period' of a wave: 1. It is represented by the symbol T. 2. It is directly proportional to the frequency. 3. Its SI unit is Hertz. Which of the statements given above is/are correct?
Which of the following best describes the 'Wavelength' of a sound wave?
In the context of sound, what is 'Reverberation'?
Which of the following materials would be most suitable for reducing reverberation in a hall?
Consider the following statements about the propagation of sound: 1. Sound travels as a wave. 2. The disturbance remains stationary while the medium moves. 3. The particles of the medium oscillate back and forth. Which of the statements given above are correct?
With reference to the structure of a sound wave, a 'Valley' in the density-distance graph corresponds to:
Consider the following statements regarding the speed of sound: 1. Speed of sound in air at 0°C is 500 m/s. 2. Speed of sound in air at 22°C is 344 m/s. 3. Speed of sound in water is greater than in air. Which of the statements given above are correct?
In the context of wave mechanics, what does the term 'Frequency' refer to?
How does the speed of sound change when it propagates from a gaseous medium (air) to a liquid medium (water)?
Consider the following statements about the 'Hearing Aid': 1. It is a battery-operated electronic device. 2. The microphone converts electrical signals into sound. 3. The speaker converts sound waves into electrical signals. Which of the statements given above is/are correct?
Which of the following correctly represents the order of speed of sound ($v$) in different media?
What is the effect of temperature on the speed of sound in a gas?
With reference to the properties of sound, which of the following statements regarding a musical 'note' is incorrect?
Consider the following statements regarding the 'Amplitude' of a sound wave: 1. It is represented by the letter Z. 2. Its unit is the same as that of density or pressure. 3. It depends upon the force with which an object is made to vibrate. Which of the statements given above are correct?
Which of the following statements about 'Ultrasonography' is correct?
Consider the following statements regarding the reflection of sound in a stethoscope: 1. The sound of the patient's heartbeat reaches the doctor's ears by multiple reflection. 2. The tube of the stethoscope absorbs the sound to prevent echoes. Which of the statements given above is/are correct?
Which of the following best explains why sound cannot travel through a vacuum?
What is the primary purpose of designing curved ceilings in concert halls and cinema halls?