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 2 Sound (ध्वनि) Ch(11)Practice Quiz in Hindi Part – 2 || Class 9 Science Practice Quizzes in English 1 / 201. The SI unit of frequency is: A. Meter B. Pascal C. Second D. Hertz Explanation: Hertz (Hz) is equivalent to cycles per second. 2 / 202. Ultrasound is used for: A. All of the above B. Detecting cracks in metal blocks C. Medical imaging D. Cleaning objects Explanation: Ultrasound has a wide range of applications due to its ability to travel along well-defined paths and penetrate various materials. 3 / 203. 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. 4 / 204. Which of the following is NOT a characteristic of a sound wave? A. Speed B. Amplitude C. Medium D. Frequency 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. 5 / 205. Echocardiography is a technique that uses: A. Light waves B. Infrasonic waves C. Ordinary sound waves D. Ultrasonic waves Explanation: It is used to create images of the heart by analyzing the reflected ultrasound waves. 6 / 206. Ultrasonic waves are used to detect cracks in metal blocks because: A. They have a high frequency and can be reflected by small defects B. They are audible to humans C. They can bend around corners D. They travel slower than ordinary sound waves Explanation: Ordinary sound waves would diffract around the cracks, making them difficult to detect. 7 / 207. The speed of sound in a medium is highest in: A. Vacuum B. Solids C. Gases D. Liquids Explanation: The closer the particles of the medium, the faster the sound wave can be transmitted. 8 / 208. A sound of single frequency is called: A. Noise B. Pitch C. Note D. Tone Explanation: A musical note is composed of multiple tones. 9 / 209. Ultrasonography is used for: A. Cleaning objects B. Examining the foetus during pregnancy C. Detecting cracks in metal blocks D. Breaking kidney stones Explanation: It helps to detect any abnormalities in the foetus. 10 / 2010. The ceilings of concert halls are often curved to: A. Focus sound in a particular direction B. Increase the speed of sound C. Ensure even distribution of sound D. Reduce reverberation Explanation: The curved shape helps to reflect sound waves to all corners of the hall. 11 / 2011. The quality or timbre of sound helps us to: A. Determine the speed of sound B. Distinguish between sounds of the same frequency and amplitude but from different sources C. Distinguish between sounds of different amplitudes D. Distinguish between sounds of different frequencies Explanation: Timbre allows us to differentiate between the sound of a guitar and a piano playing the same note. 12 / 2012. The pitch of a sound is determined by its: A. Frequency B. Amplitude C. Speed D. Loudness Explanation: A higher frequency corresponds to a higher pitch. 13 / 2013. Sounds of frequencies below 20 Hz are called: A. Infrasound B. Supersonic sound C. Ultrasound D. Audible sound Explanation: Infrasound is used by some animals for communication. 14 / 2014. Frequencies higher than 20 kHz are called: A. Infrasound B. Supersonic sound C. Audible sound D. Ultrasound Explanation: Ultrasound has various applications in medicine and industry. 15 / 2015. A hearing aid: A. Reduces reverberation B. Increases the speed of sound C. Amplifies sound waves D. Produces sound Explanation: It helps people with hearing loss to hear sounds more clearly. 16 / 2016. Breaking kidney stones into fine grains using sound waves is called: A. Echocardiography B. Sonoluminescence C. Lithotripsy D. Ultrasonography Explanation: This technique uses focused ultrasound waves to break the stones. 17 / 2017. Which of the following animals can hear ultrasound? A. Humans B. Elephants C. Bats D. Dogs Explanation: Bats use ultrasound for navigation and hunting. 18 / 2018. The audible range of sound for human beings is: A. 0 Hz to 10 Hz B. 10 Hz to 10000 Hz C. 20 Hz to 20000 Hz D. 25 kHz to 50 kHz Explanation: This is the range of frequencies that most humans can hear. 19 / 2019. Which of the following is NOT an application of ultrasound? A. Imaging internal organs B. Cleaning delicate objects C. Detecting earthquakes D. Measuring the depth of the ocean Explanation: This is typically done using sonar, which utilizes sound waves within the audible range. 20 / 2020. Which of the following statements is NOT true about sound waves? A. They can be reflected. B. They are longitudinal waves. C. They are produced by vibrating objects. D. They can travel through a vacuum. Explanation: Sound waves require a medium to propagate.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 40% 0% Restart quiz Category: Class 9 Science Quizzes in English
