Q.61)-What is the unit of frequency?
- Decibel
- Watt
- Hertz
- Newton
Q.62)-Sounds of frequencies below 20 Hz are called
- Infrasonic sound
- Ultrasonic sound
- Intrasonic sound
- Reflected sound
Q.63)-What is the minimum distance(in meters) required to hear an echo?
- 10
- 13
- 17
- 21
Q.64)-Which among the following determines the pitch of a sound?
- Amplitude
- Frequency
- Loudness
- Wavelength
Q.65)-What is the SI unit of frequency?
- Newton
- Watt
- Farad
- Hertz
Q.66)-Who pioneered diagnostic ultrasound?
- Alexander fleming
- Ian Donald
- A.Laveran
- Robert Koch
Q.67)-What is the SI unit of intensity of sound?
- Decibel
- Newton
- Heartz
- Tesla