Sound (ध्वनि) Ch(11) Practice Quiz in Hindi Part – 1 – Class 9 Science Practice Quizzes in English Posted on February 28, 2025February 28, 2025 by Anshul Gupta0% 0 votes, 0 avg 3 Sound (ध्वनि) Ch(11)Practice Quiz in Hindi Part – 1 || Class 9 Science Practice Quizzes in English 1 / 201. The time taken for one complete oscillation is called: A. Time period B. Wavelength C. Frequency D. Amplitude Explanation: Time period is measured in seconds. 2 / 202. Sound is produced by: A. Vibrating objects B. Light waves C. Stationary objects D. Heat energy Explanation: Vibrations create disturbances in the surrounding medium, which propagate as sound waves. 3 / 203. The substance through which sound is transmitted is called a: A. Conductor B. Insulator C. Medium D. Vacuum Explanation: A medium can be a solid, liquid, or gas. Sound cannot travel through a vacuum. 4 / 204. Sound waves are characterized by: A. The motion of particles parallel to the direction of wave propagation B. The transfer of particles through the medium C. The motion of particles perpendicular to the direction of wave propagation D. The absence of particle motion Explanation: This type of wave is called a longitudinal wave. 5 / 205. The distance between two consecutive compressions or rarefactions is called: A. Time period B. Amplitude C. Wavelength D. Frequency Explanation: Wavelength is the distance over which the wave’s shape repeats. 6 / 206. The minimum distance of the obstacle from the source of sound for hearing a distinct echo is: A. Dependent on the speed of sound only B. 8.6 m C. 34.4 m D. 17.2 m Explanation: This distance is calculated based on the speed of sound in air and the time required to hear a distinct echo. 7 / 207. Megaphones and horns are designed to: A. Spread sound in all directions B. Send sound in a particular direction C. Increase the frequency of sound D. Reduce the speed of sound Explanation: They use multiple reflections to focus the sound waves. 8 / 208. A stethoscope is used for: A. Measuring the speed of sound B. Listening to sounds produced within the body C. Amplifying sound waves D. Reducing reverberation Explanation: It uses multiple reflections to transmit the sound of the patient’s heartbeat to the doctor’s ears. 9 / 209. Sound is a form of: A. Light energy B. Kinetic energy C. Mechanical energy D. Potential energy Explanation: Sound is produced by vibrations, which involve the movement of particles. This movement is a form of mechanical energy. 10 / 2010. Reverberation is: A. The absorption of sound waves B. The repetition of a sound due to reflection from a surface C. The persistence of sound due to repeated reflections D. The bending of sound waves Explanation: Reverberation can be reduced by using sound-absorbing materials on the walls and ceilings of a room. 11 / 2011. A region of high pressure in a sound wave is called: A. Crest B. Rarefaction C. Trough D. Compression Explanation: Compression is formed when the vibrating object pushes the air particles closer together. 12 / 2012. The speed of sound is: A. Constant in all media B. Dependent on the properties of the medium C. Not affected by temperature D. Always faster in solids than in liquids Explanation: The speed of sound is generally higher in denser materials. 13 / 2013. The speed of sound in air at 0°C is approximately: A. 344 m/s B. 1531 m/s C. 5950 m/s D. 331 m/s Explanation: The speed of sound in air increases with temperature. 14 / 2014. The number of oscillations per unit time is called: A. Frequency B. Amplitude C. Wavelength D. Time period Explanation: Frequency is measured in Hertz (Hz). 15 / 2015. The law of conservation of energy states that: A. Energy can be destroyed B. Energy cannot be created or destroyed, only transformed C. Energy is always constant D. Energy can be created Explanation: The law of conservation of energy states that energy cannot be created or destroyed, but it can be converted from one form to another. 16 / 2016. A region of low pressure in a sound wave is called: A. Compression B. Crest C. Rarefaction D. Trough Explanation: Rarefaction is formed when the vibrating object moves backward, creating more space between the air particles. 17 / 2017. To hear a distinct echo, the time interval between the original sound and the reflected sound should be at least: A. 10 s B. 1 s C. 0.1 s D. 0.01 s Explanation: This is because the sensation of sound persists in our brain for about 0.1 s. 18 / 2018. When an object vibrates, it causes: A. The particles of the medium to travel all the way to the listener B. The particles of the medium to vibrate in a chain reaction C. The medium to remain stationary D. The speed of sound to decrease Explanation: The vibration of one particle causes the adjacent particles to vibrate, transmitting the sound wave. 19 / 2019. An echo is: A. The bending of sound waves B. The absorption of sound waves C. The persistence of sound due to repeated reflections D. The repetition of a sound due to reflection from a surface Explanation: An echo is heard when the reflected sound wave reaches the listener’s ear after the original sound wave has ended. 20 / 2020. The reflection of sound follows: A. Different laws than light reflection B. The same laws as light reflection C. Only the law of refraction D. No specific laws Explanation: The angle of incidence equals the angle of reflection, and the incident sound wave, reflected sound wave, and the normal to the surface all lie in the same plane. 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 55% 0% Restart quiz Category: Class 9 Science Quizzes in English
