MCQ Science and Technology Class 9 Chapter 12 महाराष्ट्र Board Study of Sound 1. What are sounds below 20 Hz called?UltrasoundAudible soundInfra soundSupersonic soundQuestion 1 of 202. What are sounds above 20,000 Hz called?Infra soundAudible soundUltrasoundSubsonic soundQuestion 2 of 203. Which of the following is an example of infra sound?Sound of a whistleSound produced by a pendulumSound of a loudspeakerSound of a musical instrumentQuestion 3 of 204. Which animal can hear infra sounds, as per the document?TigerDogLionElephantQuestion 4 of 205. Who discovered that bats use their ears to navigate in the dark?BorelliVivianiSpallanzaniNewtonQuestion 5 of 206. What is one application of ultrasonic sound mentioned in the document?Generating heatSterilizing liquids like milkCreating lightMeasuring temperatureQuestion 6 of 207. What is used to obtain images of internal organs in the human body?Infra soundUltrasonic soundAudible soundRadio wavesQuestion 7 of 208. What technology is used to locate cracks and faults in metal blocks?X-rayUltrasonic soundMRIRadarQuestion 8 of 209. In the sound reflection activity, what must be adjusted to hear the clock’s ticking clearly?Length of the tubesAngles of the tubesDistance from the wallSize of the clockQuestion 9 of 2010. What surface is required for the reflection of sound?Soft and porousSmooth or roughTransparentAbsorbentQuestion 10 of 2011. Which material is a bad reflector of sound?GlassCurtainsMetalWoodQuestion 11 of 2012. What happens if one tube is lifted in the sound reflection activity?Sound becomes louderSound reflection stopsSound becomes clearerSound travels fasterQuestion 12 of 2013. What is an echo caused by?Absorption of soundReflection of sound by a surfaceGeneration of new soundMixing of soundsQuestion 13 of 2014. At 22°C, what is the minimum distance between the source and reflecting surface for a distinct echo?8.6 m17.2 m34.4 m68.8 mQuestion 14 of 2015. What is the velocity of sound in air at 22°C, as per the document?332 m/s340 m/s344 m/s350 m/sQuestion 15 of 2016. What causes reverberation in a room?Single reflection of soundMultiple reflections of soundAbsorption of soundGeneration of new soundQuestion 16 of 2017. Why do some auditoriums have inferior sound reception?Due to sound absorptionDue to reverberationDue to low sound intensityDue to soft wallsQuestion 17 of 2018. What does SONAR use to determine the distance of underwater objects?Light wavesUltrasonic sound wavesInfra sound wavesAudible sound wavesQuestion 18 of 2019. What is SONAR used to search for?AirplanesSunken shipsLandminesSatellitesQuestion 19 of 2020. What technology generates images of a foetus in a pregnant woman?X-raySonographyCT scanMRIQuestion 20 of 20 Loading...
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