"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


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