4. Propagation of sound
Sound is transmitted by particles (atoms or
molecules) in a solid, liquid or gas colliding
with each other. It is a wave which is created by
vibrating objects and propagated through a
medium (solid, liquid or gas) from one location to
another.
6. Types of wave
Longitudinal waves – the wave in which the
particles of medium vibrates to and fro in the
same direction in which wave is moving.
Transverse wave – the wave in which the particles of
medium vibrates up and down to the direction in
which the wave is moving .
12. Reflection of sound
• Multiple reflection of sound is the process in
which sound waves bounces off
obstacles and reflects many times before reaching the
destination. this is the
phenomena that occurs in a stethoscope. sound waves
reflect through the
tube many times before reaching the ears of the
doctor. It is very helpful in
detecting problems.
13. Reverberation
• Reverberation is the persistence of sound in a
particular space after
the original sound is removed. A reverberation,
or reverb, is created
when a sound is produced in an enclosed space
causing a large number
of echoes to build up and then slowly decay as the
sound is absorbed by
the walls and air.
14. Range of hearing
• Hearing range usually describes the range of
frequencies that can
be heard by an animal or human, though it can
also refer to the range of levels.
In humans the audible range of frequencies is
usually said to be 20 Hz (cycles per second) to
20 kHz (20,000 Hz) .
15. SONAR
Sonar stands for sound navigation and
ranging .
Sonar is a device that uses ultrasonic waves
to measure the distance , direction and speed
underwater objects .
16. Human ear
The ear is the anatomical organ that
detects sound. It not only acts as a
receiver for sound, but also plays a major role
in the sense of balance and
body position. The ear is part of the auditory
system.
19. A sound wave travels from east to west, in
which direction do the particles of air
move?
(A) East – west
(B) North - south
(C) Up and down
(D) None
20. . In which medium sound travels
faster ?
(A) Solid
(C) Gas
(B) Liquid
(D) None
21. What is the name of short duration
wave?
(A) Pulse
(C) Time period
(B) Frequency
(D) Velocity
22. What is the velocity of sound in
water at room temperature?
(A)1500 m/s
(B) (B) 330 m/s
(C) 1500 km/s
(D) 330 km/s
23. The unit of quantity on which pitch
of the sound depends is :
(A)Hertz
(B) meter
(C) meter/second
(D) second
24. The unit of quantity on which
loudness of found depends is :
(A) meter
(B) Hertz
(C) meter/second
(D) second
25. Nature of sound wave is :
(A) transverse
(B) longitudinal
(C) electromagnetic
(D) seism
26. Pitch of high frequency sound is :
(A) high
(C) zero
(B) low
(D) infinite
27. Voice of a friend is recognized by its :
(A) Pitch
(C) Intensity
(B) quality
(D) velocity
28. Sound waves in air are :
(A)Longitudinal waves
(B) Radio waves
(C) Transverse waves
(D) Electromagnetic waves