Test understanding. select the Correct Answer
What is the loudness of normal breathing?
- 10dB
- 30dB
- 5dB
- 60dB
Cats can hear frequencies upto-
- 40,000Hz
- 70,000Hz
- 50,000Hz
- 60,000Hz
Which waves can be used to break kidney stones?
- Radiowaves
- Microwaves
- Ultrasound
- Gamma waves
Which waves can be used to detect cracks in metal objects?
- Radiowaves
- Infrared
- Ultrasound
- None of these
What is pleasant sound called?
- Noise
- Music
- Roar
- Tune
Which measures can reduce noise?
- Plantation along roadside
- Silencers in vehicle
- Horn minimisation
- All of these
Metal reeds are used in-
- Guitar
- Violin
- Tabla
- Harmonium
Drum uses this to produce sound-
- String
- Membrane
- Reeds
- Air column
what are the sources in home that produces noise?
- Television
- Transistors
- Coolers
- Air conditioners
- All of these
At which intensity noise becomes painful?
- 50dB
- 60dB
- 70dB
- 80dB