31) The minimum intensity of sound which a normal human ear can detect is expressed
Ans) 10 DB
32) The velocity of sound in air does not change with a change in
Ans) Air pressure
33)Stethoscope which is used by doctors works on which principle
Ans) Reflection of Sound
34) What is studied in Acoustics
Ans) Sound
35) Bats can detect obstacles because they generate ( general science objective questions)
Ans) Ultrasonic sound waves
36) What is the approximate frequency of ultrasonic waves
Ans) More than 20000 Hz
37) The sound of a wave has maximum velocity
Ans) In solid
38) According to the world health organization’s standard audio capability range of a healthy human being is
Ans) 5-10 DB
39) What is the sound wave propagation in gas
Ans) Adiabatic Compression and rarefaction
40) A therm is a unit of
Ans) Heat
