1. To hear a distinct echo each time interval between the original sound and the reflected sound must be:

2. The reciprocal of frequency is

3. If a wave complete 20 vibration in 2.5 s, then its frequency is

4. In a longitudinal wave, the individual particle of the medium move

5. A boat is set into vertical Vibration by waves of speed 5 ms-1 whose crests are 5m apart. The Time period of vertical vibration of the boat is

6. The lowest audible frequency for a human being is about

7. Which part of human ear converts sound vibrations into electrical signals

8. Which characteristic is this? We can distinguish between sound having same pitch and loudness.

9. In a transverse wave, the individual particle of the medium move

10. Reverberation of sound is used in

11. When we pluck the wire of a sitar, the waves produced in its wire are :

12. If the distance between a crest and and its consecutive trough is L, then the wavelength of the wave is given by

13. A tuning fork is vibrating in the air. The number of compressions going past a given point per second

14. Waves formed over water surface are

15. Sound travels through which medium ?