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