Q.51)-Conversion of sound energy into electrical energy is done by
  • Solar cell
  • Gramophone
  • Microphone
  • Loud speaker
Q.52)-A bomb explodes on the moon. You will hear its sound on earth after….
  • 20 minutes
  • 2 hours 20 minutes
  • 3.7 hours
  • You cannot hear the sound of explosion
Q.53)-Bats can sense obstacles because they produce
  • Supersonic sound waves
  • Ultrasonic sound waves
  • Infrasonic sound waves
  • Micro sound waves
Q.54)-Quality of a musical note depedns on
  • Fundamental of frequency
  • Amplitude of the wave
  • Harmonics present
  • Velocity of sound in the medium
Q.55)-Which of the following is the unit of perceived loudness of sound?
  • Decibel
  • Sone
  • Hertz
  • Phon
Q.56)-Hydroscope is an instrument that shows changes in
  • Sound under water
  • Atmospheric humidity
  • Density of liquid
  • Elevation of land
Q.57)-The SI unit of intensity of sound is
  • Watt per square meter
  • Joule per square meter
  • Newton per square meter
  • Tesla per square meter
Q.58)-Women have shrill voice because of
  • Low frequency
  • High frequency
  • Shrill vocals
  • Strong epiglottis
Q.59)-The instrument used to study the laws of vibrating string is
  • Hydrometer
  • Sonometer
  • Sphygmonamometer
  • Electrometer
Q.60)-In fluid mechanics, Mach number is 1, if the speed of an object is equal to the ….?
  • Speed of light
  • Rotational speed of sun
  • Speed of sound
  • Speed revolution of earth around the sun