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"Dulari Kanya", a scheme to bring down infant mortality in the state is launched by which Indian State? राय मशशुमृयुदर मकमी लानेकेलए 'दलार ु कया' योजना कस राय नेशुक है? Options: 1) Arunachal Pradesh अणाचल देश 2) Rajasthan राजथान 3) Uttar Pradesh उतर देश 4) Madhya Pradesh मय देश

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What is the minimum distance (in metres) required to hear an echo? ितिन सुननेके िलए ूनतम दू री (मीटर म) िकतनी होनी चािहए? Options: 1) 10 2) 13 3) 17 4) 21

Correct Answer: 17The velocity of sound in dry air is approximately 343 m/s at a temperature of 25 °C. Therefore, the reflecting object must be more than 17.2m from the sound source for echo to be perceived by a person located at the source....Read more