Sound (ध्वनि) Ch(11) Practice Quiz in Hindi Part – 2 || Class 9 Science Practice Quizzes in English Posted on February 28, 2025February 28, 2025 by Anshul Gupta0% 0 votes, 0 avg 1 Sound (ध्वनि) Ch(11)Practice Quiz in Hindi Part – 2 || Class 9 Science Practice Quizzes in English 1 / 201. The loudness or softness of a sound is determined by its: A. Amplitude B. Pitch C. Speed D. Frequency Explanation: A larger amplitude corresponds to a louder sound. 2 / 202. Ultrasound is used for: A. Detecting cracks in metal blocks B. Cleaning objects C. All of the above D. Medical imaging Explanation: Ultrasound has a wide range of applications due to its ability to travel along well-defined paths and penetrate various materials. 3 / 203. Ultrasonic waves are used to detect cracks in metal blocks because: A. They are audible to humans B. They travel slower than ordinary sound waves C. They have a high frequency and can be reflected by small defects D. They can bend around corners Explanation: Ordinary sound waves would diffract around the cracks, making them difficult to detect. 4 / 204. Which of the following is NOT an application of ultrasound? A. Cleaning delicate objects B. Measuring the depth of the ocean C. Imaging internal organs D. Detecting earthquakes Explanation: This is typically done using sonar, which utilizes sound waves within the audible range. 5 / 205. Echocardiography is a technique that uses: A. Light waves B. Infrasonic waves C. Ultrasonic waves D. Ordinary sound waves Explanation: It is used to create images of the heart by analyzing the reflected ultrasound waves. 6 / 206. The SI unit of frequency is: A. Hertz B. Pascal C. Meter D. Second Explanation: Hertz (Hz) is equivalent to cycles per second. 7 / 207. The speed of sound in a medium is highest in: A. Gases B. Vacuum C. Solids D. Liquids Explanation: The closer the particles of the medium, the faster the sound wave can be transmitted. 8 / 208. The quality or timbre of sound helps us to: A. Distinguish between sounds of the same frequency and amplitude but from different sources B. Distinguish between sounds of different frequencies C. Distinguish between sounds of different amplitudes D. Determine the speed of sound Explanation: Timbre allows us to differentiate between the sound of a guitar and a piano playing the same note. 9 / 209. Frequencies higher than 20 kHz are called: A. Audible sound B. Ultrasound C. Supersonic sound D. Infrasound Explanation: Ultrasound has various applications in medicine and industry. 10 / 2010. Sounds of frequencies below 20 Hz are called: A. Infrasound B. Audible sound C. Ultrasound D. Supersonic sound Explanation: Infrasound is used by some animals for communication. 11 / 2011. Ultrasonography is used for: A. Examining the foetus during pregnancy B. Detecting cracks in metal blocks C. Breaking kidney stones D. Cleaning objects Explanation: It helps to detect any abnormalities in the foetus. 12 / 2012. Breaking kidney stones into fine grains using sound waves is called: A. Sonoluminescence B. Echocardiography C. Lithotripsy D. Ultrasonography Explanation: This technique uses focused ultrasound waves to break the stones. 13 / 2013. The ceilings of concert halls are often curved to: A. Increase the speed of sound B. Ensure even distribution of sound C. Reduce reverberation D. Focus sound in a particular direction Explanation: The curved shape helps to reflect sound waves to all corners of the hall. 14 / 2014. The audible range of sound for human beings is: A. 0 Hz to 10 Hz B. 20 Hz to 20000 Hz C. 25 kHz to 50 kHz D. 10 Hz to 10000 Hz Explanation: This is the range of frequencies that most humans can hear. 15 / 2015. The pitch of a sound is determined by its: A. Speed B. Frequency C. Amplitude D. Loudness Explanation: A higher frequency corresponds to a higher pitch. 16 / 2016. Which of the following is NOT a characteristic of a sound wave? A. Speed B. Amplitude C. Frequency D. Medium Explanation: While sound needs a medium to travel, the medium itself is not a characteristic of the sound wave. The characteristics of a sound wave are frequency, amplitude, and speed. 17 / 2017. A sound of single frequency is called: A. Noise B. Note C. Tone D. Pitch Explanation: A musical note is composed of multiple tones. 18 / 2018. Which of the following animals can hear ultrasound? A. Bats B. Dogs C. Humans D. Elephants Explanation: Bats use ultrasound for navigation and hunting. 19 / 2019. Which of the following statements is NOT true about sound waves? A. They are longitudinal waves. B. They can be reflected. C. They can travel through a vacuum. D. They are produced by vibrating objects. Explanation: Sound waves require a medium to propagate.20 / 2020. A hearing aid: A. Amplifies sound waves B. Increases the speed of sound C. Produces sound D. Reduces reverberation Explanation: It helps people with hearing loss to hear sounds more clearly. Please insert your information to see your ranking अपनी Ranking जानने के लिए कृपया अपनी जानकारी भरे NamePhone Number Your score isThe average score is 35% 0% Restart quiz Category: Class 9 Science Quizzes in English
