{"id":15881,"date":"2025-11-06T07:25:50","date_gmt":"2025-11-06T07:25:50","guid":{"rendered":"https:\/\/mcqsadda.com\/?p=15881"},"modified":"2025-11-18T11:46:10","modified_gmt":"2025-11-18T11:46:10","slug":"sound-top-100-mcqs-with-answer-and-explanation-2","status":"publish","type":"post","link":"https:\/\/mcqsadda.com\/index.php\/2025\/11\/06\/sound-top-100-mcqs-with-answer-and-explanation-2\/","title":{"rendered":"Sound Top 100 MCQs With Answer and Explanation"},"content":{"rendered":"\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">1. Sound is produced due to \u2014<\/mark><\/strong><br>A) Chemical reaction<br>B) Vibration of bodies<br>C) Heat energy<br>D) Light energy<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B)Vibration of bodies <\/b><BR>\n<b>Explanation:<\/b> Sound is generated when objects vibrate and these vibrations travel through a medium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">2. The substance through which sound travels is called \u2014<\/mark><\/strong><br>A) Conductor<br>B) Medium<br>C) Channel<br>D) Material<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B) Medium <\/b><BR>\n<b>Explanation:<\/b> Sound needs a medium (solid, liquid, or gas) to propagate.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">3. Sound cannot travel through \u2014<\/mark><\/strong><br>A) Solids<br>B) Liquids<br>C) Gases<br>D) Vacuum<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: D) Vacuum<\/b><BR>\n<b>Explanation:<\/b> Sound needs a material medium; in vacuum, there are no particles to transmit vibrations.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">4. The S.I. unit of frequency is \u2014<\/mark><\/strong><br>A) Hertz (Hz)<br>B) Newton (N)<br>C) Joule (J)<br>D) Watt (W)<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A) Hertz (Hz) <\/b><BR>\n<b>Explanation:<\/b> The SI unit of frequency is the\u00a0hertz (Hz), which is equal to one cycle per second.\u00a0\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">5. The S.I. unit of sound intensity is \u2014<\/mark><\/strong><br>A) Decibel (dB)<br>B) Hertz (Hz)<br>C) Joule (J)<br>D) Pascal (Pa)<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A) Decibel (dB)<\/b><BR>\n<b>Explanation:<\/b> decibels are the standard unit used to measure sound intensity.\u00a0\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">6. Which of the following statements is true?<\/mark><\/strong><br>A) Sound travels faster in air than in solids.<br>B) Sound travels faster in solids than in gases.<br>C) Sound travels fastest in gases.<br>D) Sound cannot travel through solids.<br><strong>Answer:<\/strong> B) Sound travels faster in solids than in gases.<br><strong>Explanation:<\/strong> In solids, particles are close together, allowing faster vibration transfer.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">7. The speed of sound in air at room temperature is approximately \u2014<br><\/mark><\/strong>A) 150 m\/s<br>B) 330 m\/s<br>C) 500 m\/s<br>D) 1000 m\/s<br><strong>Answer:<\/strong> B) 330 m\/s<br><strong>Explanation:<\/strong> Speed of sound in dry air at 25\u00b0C is about 343 m\/s.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">8. The loudness of sound depends on its \u2014<\/mark><\/strong><br>A) Frequency<br>B) Amplitude<br>C) Speed<br>D) Pitch<br><strong>Answer:<\/strong> B) Amplitude<br><strong>Explanation:<\/strong> Greater amplitude \u2192 louder sound.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">9. The pitch of a sound depends on \u2014<\/mark><\/strong><br>A) Amplitude<br>B) Frequency<br>C) Wavelength<br>D) Velocity<br><strong>Answer:<\/strong> B) Frequency<br><strong>Explanation:<\/strong> Higher frequency \u2192 higher pitch.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">10. The time taken for one complete vibration is called \u2014<br><\/mark><\/strong>A) Frequency<br>B) Time period<br>C) Amplitude<br>D) Pitch<br><strong>Answer:<\/strong> B) Time period<br><strong>Explanation:<\/strong> T=1\/fT = 1\/fT=1\/f, reciprocal of frequency.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">11. The number of vibrations per second is called \u2014<br><\/mark><\/strong>A) Wavelength<br>B) Amplitude<br>C) Frequency<br>D) Pitch<br><strong>Answer:<\/strong> C) Frequency<br><strong>Explanation:<\/strong> It indicates how many vibrations occur in one second.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">12. Sound waves are \u2014<br><\/mark><\/strong>A) Transverse waves<br>B) Longitudinal waves<br>C) Electromagnetic waves<br>D) Polarized waves<br><strong>Answer:<\/strong> B) Longitudinal waves<br><strong>Explanation:<\/strong> In sound, particles vibrate parallel to direction of wave propagation.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">13. Sound travels fastest in \u2014<br><\/mark><\/strong>A) Air<br>B) Water<br>C) Iron<br>D) Vacuum<br><strong>Answer:<\/strong> C) Iron<br><strong>Explanation:<\/strong> Sound travels fastest in solids.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">14. The range of audible sound for humans is \u2014<br><\/mark><\/strong>A) 0 \u2013 100 Hz<br>B) 20 \u2013 20,000 Hz<br>C) 2,000 \u2013 2,000,000 Hz<br>D) Above 20,000 Hz<br><strong>Answer:<\/strong> B) 20 \u2013 20,000 Hz<br><strong>Explanation:<\/strong> Sounds within this range are audible to the human ear.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">15. Sound with frequency below 20 Hz is called \u2014<br><\/mark><\/strong>A) Ultrasonic<br>B) Supersonic<br>C) Infrasonic<br>D) Subsonic<br><strong>Answer:<\/strong> C) Infrasonic<br><strong>Explanation:<\/strong> Sound below 20 Hz frequency is infrasonic.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">16. Sound with frequency above 20,000 Hz is called \u2014<br><\/mark><\/strong>A) Ultrasonic<br>B) Supersonic<br>C) Hypersonic<br>D) Subsonic<br><strong>Answer:<\/strong> A) Ultrasonic<br><strong>Explanation:<\/strong> Sound waves above audible range are called ultrasonic waves.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">17. Which of the following animals can hear ultrasonic sounds?<br><\/mark><\/strong>A) Elephant<br>B) Bat<br>C) Cow<br>D) Cat<br><strong>Answer:<\/strong> B) Bat<br><strong>Explanation:<\/strong> Bats use ultrasonic waves for navigation (echolocation).<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">18. The speed of sound depends on \u2014<br><\/mark><\/strong>A) Temperature of the medium<br>B) Nature of the medium<br>C) Both A and B<br>D) Amplitude<br><strong>Answer:<\/strong> C) Both A and B<br><strong>Explanation:<\/strong> Speed varies with temperature and density of the medium.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">19. Echo is produced due to \u2014<br><\/mark><\/strong>A) Refraction of sound<br>B) Reflection of sound<br>C) Diffraction of sound<br>D) Interference of sound<br><strong>Answer:<\/strong> B) Reflection of sound<br><strong>Explanation:<\/strong> Echo is a reflected sound heard after a time gap.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">20. Minimum distance required for hearing a distinct echo is \u2014<br><\/mark><\/strong>A) 10 m<br>B) 17 m<br>C) 34 m<br>D) 50 m<br><strong>Answer:<\/strong> B) 17 m<br><strong>Explanation:<\/strong> At 343 m\/s, time gap of 0.1 s requires 17.15 m for sound to travel to and fro.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">21. Echo is heard only after a certain interval of time because \u2014<br><\/mark><\/strong>A) Sound needs time to travel to the reflecting surface and back<br>B) Sound is delayed by the ear<br>C) Sound travels slowly in air<br>D) Reflection takes time<br><strong>Answer:<\/strong> A) Sound needs time to travel to the reflecting surface and back<br><strong>Explanation:<\/strong> Echo is heard when reflected sound reaches after at least 0.1 second.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">22. Which of the following cannot produce an echo?<br><\/mark><\/strong>A) Mountain<br>B) Wall<br>C) Pillow<br>D) Building<br><strong>Answer:<\/strong> C) Pillow<br><strong>Explanation:<\/strong> Soft surfaces absorb sound, not reflect it.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">23. The persistence of sound after the source stops vibrating is called \u2014<br><\/mark><\/strong>A) Echo<br>B) Reverberation<br>C) Resonance<br>D) Reflection<br><strong>Answer:<\/strong> B) Reverberation<br><strong>Explanation:<\/strong> Reverberation is multiple reflections of sound that prolong its duration.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">24. The phenomenon of increase in amplitude when two waves of same frequency superpose is called \u2014<br><\/mark><\/strong>A) Interference<br>B) Resonance<br>C) Diffraction<br>D) Reflection<br><strong>Answer:<\/strong> B) Resonance<br><strong>Explanation:<\/strong> Resonance occurs when the frequency of external vibration matches natural frequency.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">25. The frequency of sound emitted by a vibrating object depends on \u2014<br><\/mark><\/strong>A) Amplitude<br>B) Length and tension<br>C) Medium<br>D) Loudness<br><strong>Answer:<\/strong> B) Length and tension<br><strong>Explanation:<\/strong> In strings, frequency depends on length, tension, and mass per unit length.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">26. The sound waves cannot travel through \u2014<br><\/mark><\/strong>A) Air<br>B) Water<br>C) Steel<br>D) Vacuum<br><strong>Answer:<\/strong> D) Vacuum<br><strong>Explanation:<\/strong> Sound requires a medium; vacuum has none.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">27. The sensation of sound stops soon after the source stops because of \u2014<br><\/mark><\/strong>A) Persistence of hearing<br>B) Reflection<br>C) Absorption<br>D) Refraction<br><strong>Answer:<\/strong> A) Persistence of hearing<br><strong>Explanation:<\/strong> Human ear retains sound for about 0.1 seconds after it stops.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">28. The device used to measure frequency of sound is \u2014<br><\/mark><\/strong>A) Barometer<br>B) Hygrometer<br>C) Tuning fork<br>D) Tachometer<br><strong>Answer:<\/strong> C) Tuning fork<br><strong>Explanation:<\/strong> Tuning fork produces and measures standard frequencies.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">29. In which medium does sound travel fastest?<br><\/mark><\/strong>A) Air<br>B) Water<br>C) Steel<br>D) Wood<br><strong>Answer:<\/strong> C) Steel<br><strong>Explanation:<\/strong> Solids have closely packed molecules, giving faster sound transmission.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">30. The human ear can sense sound frequencies approximately between \u2014<br><\/mark><\/strong>A) 1\u201310 Hz<br>B) 20\u201320,000 Hz<br>C) 2,000\u2013200,000 Hz<br>D) 200\u20132,000,000 Hz<br><strong>Answer:<\/strong> B) 20\u201320,000 Hz<br><strong>Explanation:<\/strong> Audible range for humans.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">31. Which of the following has the lowest speed of sound?<br><\/mark><\/strong>A) Air<br>B) Water<br>C) Steel<br>D) Iron<br><strong>Answer:<\/strong> A) Air<br><strong>Explanation:<\/strong> Sound travels slowest in gases due to large molecular separation.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">32. Ultrasonic waves are used in \u2014<br><\/mark><\/strong>A) Cooking food<br>B) Cleaning jewelry<br>C) Producing electricity<br>D) Communication through wires<br><strong>Answer:<\/strong> B) Cleaning jewelry<br><strong>Explanation:<\/strong> Ultrasonic waves remove dirt particles effectively by vibration.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">33. SONAR is used to measure \u2014<br><\/mark><\/strong>A) Distance of ship from the shore<br>B) Speed of aircraft<br>C) Depth of sea<br>D) Distance between two cities<br><strong>Answer:<\/strong> C) Depth of sea<br><strong>Explanation:<\/strong> SONAR (Sound Navigation and Ranging) uses reflected ultrasonic waves to measure depth.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">34. The principle used in SONAR is \u2014<br><\/mark><\/strong>A) Reflection of sound<br>B) Refraction of sound<br>C) Diffraction of sound<br>D) Polarization of sound<br><strong>Answer:<\/strong> A) Reflection of sound<br><strong>Explanation:<\/strong> SONAR works based on echo (reflected sound wave) principle.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">35. The range of ultrasonic waves is \u2014<br><\/mark><\/strong>A) Below 20 Hz<br>B) Between 20\u201320,000 Hz<br>C) Above 20,000 Hz<br>D) Below 10 Hz<br><strong>Answer:<\/strong> C) Above 20,000 Hz<br><strong>Explanation:<\/strong> Ultrasonic means above audible range.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">36. Bats navigate in the dark by using \u2014<br><\/mark><\/strong>A) Light<br>B) Infrasonic waves<br>C) Ultrasonic waves<br>D) Magnetic fields<br><strong>Answer:<\/strong> C) Ultrasonic waves<br><strong>Explanation:<\/strong> Bats use echolocation through ultrasonic sound.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">37. The pitch of a sound increases if \u2014<br><\/mark><\/strong>A) Frequency decreases<br>B) Frequency increases<br>C) Amplitude increases<br>D) Velocity decreases<br><strong>Answer:<\/strong> B) Frequency increases<br><strong>Explanation:<\/strong> Pitch is directly proportional to frequency.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">38. The loudness of a sound depends on \u2014<br><\/mark><\/strong>A) Frequency<br>B) Amplitude<br>C) Velocity<br>D) Medium<br><strong>Answer:<\/strong> B) Amplitude<br><strong>Explanation:<\/strong> Larger amplitude produces louder sound.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">39. In a transverse wave, particles of medium vibrate \u2014<br><\/mark><\/strong>A) Along the direction of propagation<br>B) Perpendicular to direction of propagation<br>C) In circular motion<br>D) Randomly<br><strong>Answer:<\/strong> B) Perpendicular to direction of propagation<br><strong>Explanation:<\/strong> Sound waves are longitudinal, but transverse waves vibrate perpendicular.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">40. Sound cannot travel through vacuum because \u2014<br><\/mark><\/strong>A) Sound is electromagnetic<br>B) Sound needs particles for transmission<br>C) Sound travels as light<br>D) Sound speed becomes infinite<br><strong>Answer:<\/strong> B) Sound needs particles for transmission<br><strong>Explanation:<\/strong> In vacuum, there are no particles to carry vibrations.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">41. Sound waves in air are \u2014<br><\/mark><\/strong>A) Longitudinal mechanical waves<br>B) Transverse electromagnetic waves<br>C) Transverse mechanical waves<br>D) Electromagnetic waves<br><strong>Answer:<\/strong> A) Longitudinal mechanical waves<br><strong>Explanation:<\/strong> Sound waves require a medium and particles vibrate parallel to the direction of wave motion.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">42. The unit of wavelength is \u2014<br><\/mark><\/strong>A) Second<br>B) Meter<br>C) Hertz<br>D) Newton<br><strong>Answer:<\/strong> B) Meter<br><strong>Explanation:<\/strong> Wavelength is distance between two consecutive crests or compressions \u2192 measured in meters.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">43. The relation between speed, frequency, and wavelength of a sound wave is \u2014<br><\/mark><\/strong>A) v=f\/\u03bbv = f \/ \\lambdav=f\/\u03bb<br>B) v=f+\u03bbv = f + \\lambdav=f+\u03bb<br>C) v=f\u03bbv = f \\lambdav=f\u03bb<br>D) v=f\u2212\u03bbv = f &#8211; \\lambdav=f\u2212\u03bb<br><strong>Answer:<\/strong> C) v=f\u03bbv = f \\lambdav=f\u03bb<br><strong>Explanation:<\/strong> Speed=Frequency\u00d7Wavelength\\text{Speed} = \\text{Frequency} \u00d7 \\text{Wavelength}Speed=Frequency\u00d7Wavelength.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">44. The amplitude of vibration is the measure of \u2014<br><\/mark><\/strong>A) Pitch<br>B) Loudness<br>C) Speed<br>D) Frequency<br><strong>Answer:<\/strong> B) Loudness<br><strong>Explanation:<\/strong> Loudness \u221d square of amplitude.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">45. When the amplitude of vibration increases, sound becomes \u2014<br><\/mark><\/strong>A) Softer<br>B) Louder<br>C) Sharper<br>D) Lower<br><strong>Answer:<\/strong> B) Louder<br><strong>Explanation:<\/strong> Greater amplitude \u2192 more energy \u2192 louder sound.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">46. When frequency increases, pitch \u2014<br><\/mark><\/strong>A) Decreases<br>B) Increases<br>C) Remains constant<br>D) Becomes zero<br><strong>Answer:<\/strong> B) Increases<br><strong>Explanation:<\/strong> Pitch depends directly on frequency.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">47. Which sound has higher pitch?<br><\/mark><\/strong>A) Drum<br>B) Flute<br>C) Guitar<br>D) Bass horn<br><strong>Answer:<\/strong> B) Flute<br><strong>Explanation:<\/strong> Flute produces sound of higher frequency and pitch.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">48. Which sound has lower pitch?<br><\/mark><\/strong>A) Whistle<br>B) Human voice<br>C) Drum<br>D) Bird chirping<br><strong>Answer:<\/strong> C) Drum<br><strong>Explanation:<\/strong> Drum produces low-frequency sound \u2192 lower pitch.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">49. The speed of sound increases with \u2014<br><\/mark><\/strong>A) Decrease in temperature<br>B) Increase in temperature<br>C) Increase in pressure only<br>D) Decrease in humidity<br><strong>Answer:<\/strong> B) Increase in temperature<br><strong>Explanation:<\/strong> Higher temperature \u2192 faster particle vibration \u2192 faster sound propagation.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">50. Sound travels faster in \u2014<br><\/mark><\/strong>A) Cold air<br>B) Hot air<br>C) Dry air<br>D) Vacuum<br><strong>Answer:<\/strong> B) Hot air<br><strong>Explanation:<\/strong> Speed increases with temperature and humidity.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">51. Which of the following is not a characteristic of sound?<br><\/mark><\/strong>A) Loudness<br>B) Pitch<br>C) Quality<br>D) Speed<br><strong>Answer:<\/strong> D) Speed<br><strong>Explanation:<\/strong> Speed is a physical property; loudness, pitch, and quality are characteristics of sound.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">52. The property that distinguishes two sounds of same pitch and loudness is \u2014<br><\/mark><\/strong>A) Amplitude<br>B) Frequency<br>C) Quality or Timbre<br>D) Wavelength<br><strong>Answer:<\/strong> C) Quality or Timbre<br><strong>Explanation:<\/strong> Quality gives sound its unique tone (e.g., flute vs violin).<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">53. The speed of sound in air depends mainly on \u2014<br><\/mark><\/strong>A) Frequency<br>B) Pressure<br>C) Temperature<br>D) Amplitude<br><strong>Answer:<\/strong> C) Temperature<br><strong>Explanation:<\/strong> Speed increases with temperature in gases.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">54. The range of infrasonic sound is \u2014<br><\/mark><\/strong>A) Below 20 Hz<br>B) Above 20,000 Hz<br>C) Between 20 and 20,000 Hz<br>D) 2,000\u2013200,000 Hz<br><strong>Answer:<\/strong> A) Below 20 Hz<br><strong>Explanation:<\/strong> Sounds below human hearing range are infrasonic.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">55. Which of the following animals can produce infrasonic sound?<br><\/mark><\/strong>A) Bat<br>B) Dog<br>C) Elephant<br>D) Cat<br><strong>Answer:<\/strong> C) Elephant<br><strong>Explanation:<\/strong> Elephants use infrasonic waves to communicate over long distances.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">56. The phenomenon of reflection of sound is used in \u2014<br><\/mark><\/strong>A) SONAR<br>B) LASER<br>C) RADAR<br>D) Infrared rays<br><strong>Answer:<\/strong> A) SONAR<br><strong>Explanation:<\/strong> SONAR uses reflected sound waves to determine underwater objects and depth.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">57. The instrument used to record sound is \u2014<br><\/mark><\/strong>A) Telescope<br>B) Microphone<br>C) Stethoscope<br>D) Barometer<br><strong>Answer:<\/strong> B) Microphone<br><strong>Explanation:<\/strong> A microphone converts sound into electrical signals for recording.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">58. The device used by doctors to hear heartbeat is \u2014<br><\/mark><\/strong>A) Telephone<br>B) Microphone<br>C) Stethoscope<br>D) Megaphone<br><strong>Answer:<\/strong> C) Stethoscope<br><strong>Explanation:<\/strong> It amplifies and transmits sound of heartbeat through reflection.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">59. Sound waves cannot be polarized because \u2014<br><\/mark><\/strong>A) They are transverse<br>B) They are electromagnetic<br>C) They are longitudinal<br>D) They have low frequency<br><strong>Answer:<\/strong> C) They are longitudinal<br><strong>Explanation:<\/strong> Polarization occurs only in transverse waves.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">60. The speed of sound in air at 0\u00b0C is approximately \u2014<br><\/mark><\/strong>A) 331 m\/s<br>B) 340 m\/s<br>C) 350 m\/s<br>D) 300 m\/s<br><strong>Answer:<\/strong> A) 331 m\/s<br><strong>Explanation:<\/strong> The speed of sound at 0\u00b0C is 331 m\/s and increases by about 0.6 m\/s per \u00b0C rise in temperature.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">61. Sound waves are examples of \u2014<br><\/mark><\/strong>A) Electromagnetic waves<br>B) Transverse mechanical waves<br>C) Longitudinal mechanical waves<br>D) Stationary waves<br><strong>Answer:<\/strong> C) Longitudinal mechanical waves<br><strong>Explanation:<\/strong> Sound needs a medium, and particles vibrate parallel to wave direction.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">62. The wave formed by the vibration of a stretched string is \u2014<br><\/mark><\/strong>A) Longitudinal wave<br>B) Transverse wave<br>C) Stationary wave<br>D) Random wave<br><strong>Answer:<\/strong> B) Transverse wave<br><strong>Explanation:<\/strong> In a stretched string, particles vibrate perpendicular to the direction of wave propagation.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">63. The speed of sound in a gas depends on \u2014<br><\/mark><\/strong>A) Amplitude of wave<br>B) Density and elasticity of gas<br>C) Frequency of sound<br>D) Pressure of gas<br><strong>Answer:<\/strong> B) Density and elasticity of gas<br><strong>Explanation:<\/strong> v=E\/\u03c1v = \\sqrt{E\/\u03c1}v=E\/\u03c1\u200b, where E = elasticity, \u03c1 = density.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">64. The product of wavelength and frequency of a sound wave gives \u2014<br><\/mark><\/strong>A) Amplitude<br>B) Velocity<br>C) Intensity<br>D) Power<br><strong>Answer:<\/strong> B) Velocity<br><strong>Explanation:<\/strong> v=f\u00d7\u03bbv = f \u00d7 \\lambdav=f\u00d7\u03bb<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">65. The wavelength of a sound wave in air is 1.7 m and its frequency is 200 Hz. What is its speed?<br><\/mark><\/strong>A) 200 m\/s<br>B) 300 m\/s<br>C) 340 m\/s<br>D) 400 m\/s<br><strong>Answer:<\/strong> C) 340 m\/s<br><strong>Explanation:<\/strong> v=f\u00d7\u03bb=200\u00d71.7=340\u2009m\/sv = f \u00d7 \\lambda = 200 \u00d7 1.7 = 340 \\, m\/sv=f\u00d7\u03bb=200\u00d71.7=340m\/s<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">66. Which of the following is an example of reflection of sound?<br><\/mark><\/strong>A) Echo<br>B) Doppler effect<br>C) Reverberation<br>D) Both A and C<br><strong>Answer:<\/strong> D) Both A and C<br><strong>Explanation:<\/strong> Both echo and reverberation are caused by reflection of sound.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">67. The repetition of sound due to reflection is called \u2014<br><\/mark><\/strong>A) Echo<br>B) Vibration<br>C) Refraction<br>D) Interference<br><strong>Answer:<\/strong> A) Echo<br><strong>Explanation:<\/strong> Echo occurs when reflected sound is heard distinctly after 0.1 s.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">68. Reverberation is undesirable in \u2014<br><\/mark><\/strong>A) Halls<br>B) Open grounds<br>C) Forests<br>D) Empty fields<br><strong>Answer:<\/strong> A) Halls<br><strong>Explanation:<\/strong> Too much reverberation causes confusion and echo overlap in halls.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">69. Reverberation in big halls can be reduced by \u2014<br><\/mark><\/strong>A) Using smooth walls<br>B) Using soft materials<br>C) Increasing ceiling height<br>D) Using hard materials<br><strong>Answer:<\/strong> B) Using soft materials<br><strong>Explanation:<\/strong> Curtains, carpets, and foam absorb sound and reduce reverberation.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">70. Which among the following does not affect the speed of sound?<br><\/mark><\/strong>A) Temperature<br>B) Pressure<br>C) Medium<br>D) Frequency<br><strong>Answer:<\/strong> D) Frequency<br><strong>Explanation:<\/strong> Speed depends only on medium and temperature, not on frequency.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">71. What is the speed of sound in water approximately?<br><\/mark><\/strong>A) 1500 m\/s<br>B) 500 m\/s<br>C) 330 m\/s<br>D) 1000 m\/s<br><strong>Answer:<\/strong> A) 1500 m\/s<br><strong>Explanation:<\/strong> In water, sound travels faster than in air due to higher density.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">72. The speed of sound is maximum in \u2014<br><\/mark><\/strong>A) Air<br>B) Water<br>C) Wood<br>D) Steel<br><strong>Answer:<\/strong> D) Steel<br><strong>Explanation:<\/strong> Sound travels fastest in solids; among them, steel has high elasticity.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">73. The pitch of a sound depends on \u2014<br><\/mark><\/strong>A) Frequency<br>B) Amplitude<br>C) Loudness<br>D) Wavelength<br><strong>Answer:<\/strong> A) Frequency<br><strong>Explanation:<\/strong> Pitch increases with frequency.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">74. The loudness of a sound is determined by \u2014<br><\/mark><\/strong>A) Frequency<br>B) Amplitude<br>C) Velocity<br>D) Time period<br><strong>Answer:<\/strong> B) Amplitude<br><strong>Explanation:<\/strong> Loudness \u221d square of amplitude.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">75. A sound of 60 dB is how many times louder than 30 dB?<br><\/mark><\/strong>A) 10 times<br>B) 100 times<br>C) 1000 times<br>D) 2 times<br><strong>Answer:<\/strong> B) 100 times<br><strong>Explanation:<\/strong> Loudness level increases tenfold for every 10 dB rise \u2192 30 dB difference = 1000\/10 \u2248 100\u00d7 louder.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">76. The speed of sound increases with \u2014<br><\/mark><\/strong>A) Decrease in density<br>B) Increase in temperature<br>C) Increase in wavelength<br>D) Decrease in amplitude<br><strong>Answer:<\/strong> B) Increase in temperature<br><strong>Explanation:<\/strong> Higher temperature means faster molecular motion \u2192 faster sound transmission.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">77. Which physical quantity remains constant when sound passes from one medium to another?<br><\/mark><\/strong>A) Speed<br>B) Frequency<br>C) Wavelength<br>D) Amplitude<br><strong>Answer:<\/strong> B) Frequency<br><strong>Explanation:<\/strong> Frequency is determined by the source; it does not change with medium.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">78. The sound waves that cannot be heard by human ear are \u2014<br><\/mark><\/strong>A) Audible<br>B) Ultrasonic and infrasonic<br>C) Musical<br>D) Mechanical<br><strong>Answer:<\/strong> B) Ultrasonic and infrasonic<br><strong>Explanation:<\/strong> Humans can hear only between 20\u201320,000 Hz; others are inaudible.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">79. Sound waves transfer \u2014<br><\/mark><\/strong>A) Matter only<br>B) Energy only<br>C) Both matter and energy<br>D) Neither<br><strong>Answer:<\/strong> B) Energy only<br><strong>Explanation:<\/strong> Sound waves carry energy, not matter, from one point to another.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">80. When a sound wave travels through air, the air particles \u2014<br><\/mark><\/strong>A) Move with the wave<br>B) Vibrate to and fro about their mean position<br>C) Move randomly<br>D) Move upward only<br><strong>Answer:<\/strong> B) Vibrate to and fro about their mean position<br><strong>Explanation:<\/strong> Sound is a longitudinal wave; particles oscillate back and forth around their equilibrium.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">81. The loudness of a sound depends on \u2014<br><\/mark><\/strong>A) Frequency<br>B) Amplitude of vibration<br>C) Wavelength<br>D) Velocity of sound<br><strong>Answer:<\/strong> B) Amplitude of vibration<br><strong>Explanation:<\/strong> Greater amplitude \u2192 louder sound \u2192 more energy in vibration.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">82. The frequency of a note produced by a guitar string depends on \u2014<br><\/mark><\/strong>A) Length, tension, and thickness of string<br>B) Volume of air<br>C) Shape of instrument<br>D) Temperature of air<br><strong>Answer:<\/strong> A) Length, tension, and thickness of string<br><strong>Explanation:<\/strong> These three factors determine the frequency and hence the pitch.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">83. Sound energy is a form of \u2014<br><\/mark><\/strong>A) Chemical energy<br>B) Mechanical energy<br>C) Electrical energy<br>D) Magnetic energy<br><strong>Answer:<\/strong> B) Mechanical energy<br><strong>Explanation:<\/strong> Sound is produced by mechanical vibrations of particles.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">84. The frequency of a vibrating tuning fork increases if \u2014<br><\/mark><\/strong>A) Its length increases<br>B) Its length decreases<br>C) Its material changes<br>D) Temperature decreases<br><strong>Answer:<\/strong> B) Its length decreases<br><strong>Explanation:<\/strong> Shorter fork \u2192 higher frequency \u2192 higher pitch.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">85. The sound produced by a drum is \u2014<br><\/mark><\/strong>A) Low pitch and loud<br>B) High pitch and soft<br>C) High pitch and loud<br>D) Low pitch and soft<br><strong>Answer:<\/strong> A) Low pitch and loud<br><strong>Explanation:<\/strong> Drum vibrations are large and slow \u2192 low frequency (low pitch) but large amplitude (loud).<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">86. The sound produced by a whistle is \u2014<br><\/mark><\/strong>A) High pitch<br>B) Low pitch<br>C) Loud<br>D) Harsh<br><strong>Answer:<\/strong> A) High pitch<br><strong>Explanation:<\/strong> Whistle produces sound with high frequency \u2192 high pitch.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">87. The sound produced by a flute is \u2014<br><\/mark><\/strong>A) High pitch<br>B) Low pitch<br>C) Loud<br>D) Unpleasant<br><strong>Answer:<\/strong> A) High pitch<br><strong>Explanation:<\/strong> Flute produces musical, high-frequency sound.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">88. The quality of sound helps us to \u2014<br><\/mark><\/strong>A) Identify loudness<br>B) Distinguish between two sounds of same pitch and loudness<br>C) Measure frequency<br>D) Measure amplitude<br><strong>Answer:<\/strong> B) Distinguish between two sounds of same pitch and loudness<br><strong>Explanation:<\/strong> Quality (timbre) makes each sound unique, e.g., violin vs flute.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">89. The ear converts sound waves into \u2014<br><\/mark><\/strong>A) Light energy<br>B) Electrical impulses<br>C) Heat<br>D) Magnetic energy<br><strong>Answer:<\/strong> B) Electrical impulses<br><strong>Explanation:<\/strong> The inner ear (cochlea) changes sound vibrations into electrical signals sent to the brain.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">90. The working principle of a megaphone is \u2014<br><\/mark><\/strong>A) Reflection of sound<br>B) Refraction of sound<br>C) Resonance<br>D) Multiple reflection<br><strong>Answer:<\/strong> D) Multiple reflection<br><strong>Explanation:<\/strong> A megaphone amplifies sound using successive reflections within its cone.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">91. The speed of sound in air increases when \u2014<br><\/mark><\/strong>A) Temperature decreases<br>B) Humidity increases<br>C) Pressure decreases<br>D) Air becomes dry<br><strong>Answer:<\/strong> B) Humidity increases<br><strong>Explanation:<\/strong> Moist air is less dense \u2192 sound travels faster.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">92. Sound cannot travel through space because \u2014<br><\/mark><\/strong>A) It moves too fast<br>B) There is no medium<br>C) It is absorbed<br>D) It is reflected back<br><strong>Answer:<\/strong> B) There is no medium<br><strong>Explanation:<\/strong> Sound requires particles to propagate; space is vacuum.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">93. Infrasonic waves have frequency \u2014<br><\/mark><\/strong>A) Below 20 Hz<br>B) Above 20,000 Hz<br>C) Between 20\u201320,000 Hz<br>D) Infinite<br><strong>Answer:<\/strong> A) Below 20 Hz<br><strong>Explanation:<\/strong> Infrasonic = frequencies lower than human hearing limit.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">94. Ultrasonic waves have frequency \u2014<br><\/mark><\/strong>A) Below 20 Hz<br>B) Between 20\u201320,000 Hz<br>C) Above 20,000 Hz<br>D) Above 2,000,000 Hz<br><strong>Answer:<\/strong> C) Above 20,000 Hz<br><strong>Explanation:<\/strong> Beyond audible range \u2192 ultrasonic waves.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">95. The range of hearing of a young human being is \u2014<br><\/mark><\/strong>A) 0\u2013100 Hz<br>B) 20\u201320,000 Hz<br>C) 200\u2013200,000 Hz<br>D) 2,000\u20132,000,000 Hz<br><strong>Answer:<\/strong> B) 20\u201320,000 Hz<br><strong>Explanation:<\/strong> Human ear can detect only sounds in this frequency range.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">96. The speed of sound in iron is approximately \u2014<br><\/mark><\/strong>A) 500 m\/s<br>B) 1500 m\/s<br>C) 3400 m\/s<br>D) 5100 m\/s<br><strong>Answer:<\/strong> D) 5100 m\/s<br><strong>Explanation:<\/strong> Sound travels fastest in solids; for iron, about 5100 m\/s.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">97. The device used to detect sound under water is \u2014<br><\/mark><\/strong>A) SONAR<br>B) RADAR<br>C) LASER<br>D) Infrared sensor<br><strong>Answer:<\/strong> A) SONAR<br><strong>Explanation:<\/strong> SONAR (Sound Navigation and Ranging) uses ultrasonic reflection to locate underwater objects.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">98. When the source of sound moves towards the listener, the pitch \u2014<br><\/mark><\/strong>A) Decreases<br>B) Increases<br>C) Remains same<br>D) Disappears<br><strong>Answer:<\/strong> B) Increases<br><strong>Explanation:<\/strong> Due to <strong>Doppler Effect<\/strong>, apparent frequency increases when source approaches.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">99. The Doppler effect in sound is used in \u2014<br><\/mark><\/strong>A) Determining speed of vehicles<br>B) Measuring temperature<br>C) Measuring density of gas<br>D) Detecting earthquake waves<br><strong>Answer:<\/strong> A) Determining speed of vehicles<br><strong>Explanation:<\/strong> Police radar guns use Doppler effect to measure speed via frequency change.<\/p>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">100. Which of the following waves can travel through vacuum?<br><\/mark><\/strong>A) Sound waves<br>B) Ultrasonic waves<br>C) Radio waves<br>D) Shock waves<br><strong>Answer:<\/strong> C) Radio waves<br><strong>Explanation:<\/strong> Radio waves are electromagnetic and can travel through vacuum, unlike sound waves.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>1. Sound is produced due to \u2014A) Chemical reactionB) Vibration of bodiesC) Heat energyD) Light energy Show Answer Answer: B)Vibration of bodies Explanation: Sound is generated when objects vibrate and these vibrations travel through a medium. 2. The substance through which sound travels is called \u2014A) ConductorB) MediumC) ChannelD) Material Show Answer Answer: B) Medium<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":{"0":"post-15881","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-blog"},"_links":{"self":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/15881","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/comments?post=15881"}],"version-history":[{"count":9,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/15881\/revisions"}],"predecessor-version":[{"id":20681,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/15881\/revisions\/20681"}],"wp:attachment":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/media?parent=15881"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/categories?post=15881"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/tags?post=15881"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}