15. Sound

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1. Why two astronauts on the moon talking to each other directly, will be unable to listen to each other? 1) The moon does not have atmosphere. 2) The moon does not have Light. 3) The moon does not have Water. 4) The moon does not have Vacuum..

2. What is the SI Unit of frequency? 1) Degree Celcius 2) Hertz 3) Meter 4) second

3. Which is correct Statement? 1) sound is produced in the Stomach of human. 2) sound travels through some material medium like solid, liquid or gas. 3) Sound can travel in Vacuum. 4) Sound waves of same frequencies produce different sound notes

4. Which unit used to expressed loudness ? 1) hertz 2) Meter 3) Frequency 4) decibel (dB).

5. What is the range of audible frequencies for human ear? 1) 200 to 20,00 Hz. 2) 20 to 20,000 Hz. 3) 10 to 10,000 Hz 4) 20 to 20,000 Db

6. Identify correct pair 1) 1 Hertz = 5 vibration/second 2) 1 Hertz = 100 vibration/second 3) 1 Hertz = 1 vibration/second 4) 1 Hertz = 10 vibration/second

7. What is Sound Levels of helicopter in Decibel ? 1) 50 dB 2) 140 dB 3) 110 dB 4) 20 dB

8. Which part of human ear converts sound vibrations into electrical signals? 1) Ossicles 2) cochlea 3) eardrum 4) Pinna or auricle

9. ------------------is the voice box . 1) Larynx 2) Stomach 3) Liver 4) Brain

10. in which medium Sound propagates fastly ? 1) Solid 2) Gas 3) all of these 4) Liquid