CHAPTER 8: WAVES 1. Waves transmit ________ from one place to another. a) Energy b) Mass c) ...
CHAPTER
8: WAVES
1.
Waves
transmit ________ from one place to another.
a) Energy
b) Mass
c) Both
d) None
2.
The waves
that require a material medium for their propagation are called
a) Matter waves
b) Electromagnetic waves
c) Carrier waves
d) Mechanical waves
3.
The
example of mechanical waves is:
a) Water and air waves
b) Radio waves
c) Infrared waves
d) Ultra violet waves
4.
Sound
waves cannot travel through:
a) Air
b) Water
c) Material medium
d) Vacuum
5.
Sound
waves do not travel in vacuum because
a) They are transverse waves
b) They are stationary waves
c)
They
require material medium for propagation
d) They do not have enough energy
6.
The
velocity of sound in vacuum is:
a)
332
−1
b)
333
−1
c)
280
−1
d)
0
−1
7.
The speed
of sound in air at 0°
is
332 −1. the speed at 2° will be:
a)
330
−1
b)
333.2
−1
c)
335
−1
d)
None of
these
8. According
to Laplace correction sound travel in air under the conditions of a) Adiabatic
b) Isothermal
c) Isobaric
d) Isochoric
9. Laplace
expression for speed of sound in a
gase
is:
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||||||
a)
|
=
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|||||
b)
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=
|
|||||
c)
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=
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|||||
d)
=
10.
If the
pressure of the gas is doubled, then the speed of sound:
a) Also doubled
b) Becomes half
c) Not affected
d) Increases four times
11.
The speed
of sound in air at 30° is approximately equal to:
a)
332
−1
b)
335
−1
c)
340
−1
d)
345
−1
e)
350
−1
12.
Increase
in velocity of sound in air for 1° rise in temperature is:
a)
0.61
−1
b)
61
−1
c)
1.61
−1
d)
2
−1
13.
The speed
of sound is greater in solids than in gases due to high value of:
a) Density
b) Pressure
c) Elasticity
d) Temperature
1
14.
The wave
speed of a wave in terms of its wavelength l and period T is:
a) v = l T
b) v = l T2
c)
v = l / T
d) v = T /l
15.
The
distance between any two consecutive crests or troughs is called
a) Frequency
b) Period
c) Wave length
d) Phase difference
16.
In a
transverse wave the distance between a crest and a trough is equal to:
a) l/2
b)
l/4
c) l
d)
2 l
17.
When two
identical waves moves in the same direction, they give rise to:
a) Standing waves
b) Interference
c) Beats
d) None of these
18.
When path
difference is an integral multiple of wavelengths, the effect is called:
a) Coherency
b) Destructive interference
c) Constructive interference
d) Phase lag
19.
Periodic
alteration of sound between maximum and minimum loudness are called
a) Interferece
b) Resonance
c) Doppler effect
d) Beats
20.
Beats can
be heard when the difference of frequency is not more than:
a) 8
b) 4
c) 10
d) 6
21. Beats are formed when two notes of
frequencies 1 and 2 ( 1 > 2) are sounded together. The beat frequency will be:
a)
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1 +
2
|
|
b)
|
1 −
2
|
|
c)
|
1+ 2
|
|
2
|
||
d)
1− 2
2
22.
The
number of beats produced per second is equal to
a) The sum of the frequencies of two
tuning
forks
b)
The
difference of the frequencies of two tuning forks
c)
The ratio
of the frequencies of two tuning forks
d)
The
frequency of either of the two tuning forks
23.
When a
wave is reflected on going from a rarer to a denser medium, then at the
boundary the reflected wave will undergo a phase change of:
a)
0o
b)
90o
c)
-90o
d)
180o
24.
When a
transverse wave is reflected on going from a denser to a rarer medium, then at
the boundary the reflected wave undergoes a phase change of:
a)
0°
b)
90°
c)
−90°
d)
180°
25.
When a
transverse wave is reflected on going from a denser medium to a rare medium,
then:
a)
There is 180° phase shift
b) There is no change in phase
c) A crest is converted into trough
d) A trough is converted into crest
26.
Phase
differce of 180° is equivalent to a path
difference of:
a)
b)
2
c)
4
d)
8
2
27. Two waves of equal frequency travelling in opposite direction produce:
a) Interference
b) Stationary waves
c) Beats
d) Doppler Effect
28. Two wave trains of the same amplitude and frequency travelling in opposite directions along the same
path in the same medium produce:
a) Resonance
b) Beats
c) Standing
waves
d) Musical
notes
29. Which property of wave motion distinguish
a travelling wave from a stationary wave:
a) amplitude
b) frequency of vibration
c) propogation
of energy
d) direction
of vibration
30. If a string vibrates in n loops, the
wavelength of stationary waves will be:
a) 2
b)
2
c)
2
d)
2
31.
Stationary
waves are generated on a string of length “l”,
its fundamental frequency is given by:
a)
1 = ×
b)
1 = 2
c)
1 = 2 ×
d)
1 = 2
32. The fixed ends of a vibrating string are
a) antinodes
b) nodes
c) overtones
d) neither nodes nor anti-nodes
33. At the open end of an organ pipe:
a) Nodes are formed
b) Antinodes are formed
c)
Either
nodes or antinodes may form
d) Neither nodes nor antinodes may form
34.
A set of
frequencies, which is multiple of fundamental frequency is called:
a) Beat frequency
b) Harmonics
c) Doppler frequencies
d) Nodal frequencies
35.
The
points of maximum displacement on a stationary wave is called
a) Anti-node
b) Node
c) Trough
d) Crest
36.
In
vibrating cord the points where the amplitude is zero, are called.
a) Antinodes
b) Nodes
c) Troughs
d) Crests
37.
A
distance between two consecutive nodes is:
a)
b)
2
c)
4
d)
8
38. Radar system is an application of:
a) Interferece
b) Beats
c) Stationary waves
d) Doppler effect
39. Stars moving towards the earth show:
a) Blue shift
b) Red shift
c) No shift
d) Longer wavelength
40.
Which of
the following does not have any effect on the speed of sound in gases?
a) Temperature
b) Density
c) Pressure
d) None of these
41.
In a
stationary wave, the particle velocity at the node is:
a) Maximum
b) Minimum
c) Zero
d) Constant
3
42. Doppler Effect applies to
a) Sound wave only
b) Light wave only
c) Both sound and light wave
d) Neither sound nor light wave
43.
When the
source of sound moves away from a stationary listener, then
___________occurs:
a) An apparent increase in frequency
b) An apparent decrease in frequency
c) An apparent decrease in wavelength
d) An apparent change in frequency
44.
A simple
pendulum has a bob of mass „m‟ and its frequency is „f‟. If we replaced the bob
with a heavier one, say of „2m‟, then what will be its new frequency?
a) 1/4f
b) 1/2f
c) f
d) 2f
45.
The
distance between a node and anti-node is
a)
b)
2
c)
4
d)
8
46.
The
distance between two consecutive antinodes is:
a)
2
b)
4
c)
d)
8
47. In open organ pipe
a) Only even harmonics are present
b) Only odd harmonic are present
c)
Both even
and odd harmonics are present
d) Selected harmonics are present
Q. No.
|
Ans.
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Q. No.
|
Ans.
|
Q. No.
|
Ans.
|
1
|
a
|
17
|
b
|
33
|
b
|
2
|
d
|
18
|
c
|
34
|
b
|
3
|
a
|
19
|
d
|
35
|
a
|
4
|
d
|
20
|
c
|
36
|
b
|
5
|
c
|
21
|
b
|
37
|
b
|
6
|
d
|
22
|
b
|
38
|
d
|
7
|
b
|
23
|
d
|
39
|
a
|
8
|
a
|
24
|
a
|
40
|
c
|
9
|
c
|
25
|
b
|
41
|
c
|
10
|
c
|
26
|
b
|
42
|
c
|
11
|
e
|
27
|
b
|
43
|
b
|
12
|
a
|
28
|
c
|
44
|
c
|
13
|
c
|
29
|
c
|
45
|
c
|
14
|
c
|
30
|
a
|
46
|
a
|
15
|
c
|
31
|
b
|
47
|
c
|
16
|
a
|
32
|
b
|
COMMENTS