Q.41)-The frequency of ultrasound wave is typically
- Above 20,000 KHz
- Above 20 Khz
- Below 02 KHz
- Below 2000 KHz
Q.42)-The velocity of sound in air
- Decreases with increase of temperature
- Increase with decrease of temperature
- Does not depend on tempearture
- Decreases with decrease in temperature
Q.43)-The device which converts sound energy into electrical energy is called
- Amplifier
- Speaker
- Microphone
- Transmitter
Q.44)-Least aduible sound for most of the human ear is
- 10.0 µ bar
- 0.0002 µ bar
- 0.005 µ bar
- 5.0 µ bar
Q.45)-The ordinary and maximum tolerance limit of sound by human being is
- 50 dB to 70 dB (decibel)
- 60 dB to 80 dB (decibel)
- 65 dB to 75 dB (decibel)
- 70 to dB to 85 dB (decibel)
Q.46)-Sound is heard over longer distances on rainy days because
- Sound travels slowly in moist air
- Sound travels faster in moist air
- Moist air does not absorb sound
- Moist air absorbs sound
Q.47)-Which of the following property of sound is affected by change in air temperature
- Frequency
- Intensity
- Amplitude
- Wavelength
Q.48)-A person standing on a railway platform listens to the whistles of arriving and departing trains.
- The same in both cases in all respects
- Of higher intensity when train arrives
- Of higher pitch when train arrives
- Of higher pitch when train departs
Q.49)-Which term is not associated with sound wave?
- Hertz
- Decibel
- Candela
- Mach
Q.50)-If density of oxygen is 16 times that of hydrogen. What will be their corresponding ratio of velocity of sound?
- 4:01
- 2:01
- 1:16
- 1:04