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