The SPARK Institute of Language & Sciences

PHYSICS-I WAVE MOTION TEST 1 & 2

TEST 1
1. Let f be the frequency, v the speed, and T the period of a sinusoidal traveling wave. The correct
relationship is:
A. f = 1/T B. f = v + T C. f = vT
D. f = v/T E. f = T /v
2. Let f be the frequency, v the speed, and T the period of a sinusoidal traveling wave. The angular
frequency is given by:
A. 1/T B. 2π/T C. vT
D. f /T E. T /f
3. The displacement of a string is given by y(x, t) = ym sin(kx + ωt). The wavelength of the wave is:
A. 2πk/ω B. k/ω C. ωk
D. 2π/k E. k/2π
4. The displacement of a string is given by y(x, t) = ym sin(kx + ωt). The speed of the wave is:
A. 2πk/ω B. ω/k C. ωk
D. 2π/k E. k/2π
5. A wave is described by y(x, t) = 0.1 sin(3x − 10t), where x is in meters, y is in centimeters, and t is in
seconds. The angular frequency is:
A. 0.10 rad/s B. 3.0π rad/s C. 10π rad/s
D. 20π rad/s E. 10 rad/s
6. Water waves in the sea are observed to have a wavelength of 300 m and a frequency of 0.07 Hz.
The speed of these waves is:
A. 0.00021 m/s B. 2.1 m/s C. 21 m/s
D. 210 m/s E. none of these
7. Sinusoidal water waves are generated in a large ripple tank. The waves travel at 20 cm/s and their
adjacent crests are 5.0 cm apart. The time required for each new whole cycle to be generated is:
A. 100 s B. 4.0 s C. 2.0 s
D. 0.5 s E. 0.25 s
8. A sinusoidal transverse wave is traveling on a string. Any point on the string:
A. moves in the same direction as the wave
B. moves in simple harmonic motion with a different frequency than that of the wave
C. moves in simple harmonic motion with the same angular frequency as the wave
D. moves in uniform circular motion with a different angular speed than the wave
E. moves in uniform circular motion with the same angular speed as the wave
9. Any point on a string carrying a sinusoidal wave is moving with its maximum speed when:
A. the magnitude of its acceleration is a maximum
B. the magnitude of its displacement is a maximum
C. the magnitude of its displacement is a minimum
D. the magnitude of its displacement is half the amplitude
E. the magnitude of its displacement is one-fourth the amplitude
10. A string carries a sinusoidal wave with an amplitude of 2.0 cm and a frequency of 100 Hz. The
maximum speed of any point on the string is:
A. 2.0 m/s B. 4.0 m/s C. 6.3 m/s
D. 13 m/s E. NONE of above

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The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2
11. A transverse traveling sinusoidal wave on a string has a frequency of 100 Hz, a wavelength of
0.040 m, and an amplitude of 2.0 mm. The maximum velocity in m/s of any point on the string is:
A. 0.2 B. 1.3 C. 4
D. 15 E. 25
12. A transverse traveling sinusoidal wave on a string has a frequency of 100 Hz, a wavelength of
0.040 m, and an amplitude of 2.0 mm. The maximum acceleration in m/s 2 of any point on the
string is:
A. 0 B. 130 C. 395
D. 790 E. 1600
13. The speed of a sinusoidal wave on a string depends on:
A. the frequency of the wave B. the wavelength of the wave
C. the length of the string D. the tension in the string
E. the amplitude of the wave
14. For a given medium, the frequency of a wave is:
A. independent of wavelength B. proportional to wavelength
C. inversely proportional to wavelength D. proportional to the amplitude
E. inversely proportional to the amplitude
15. The tension in a string with a linear mass density of 0.0010 kg/ is 0.40 N. A sinusoidal wave with a
wavelength of 20 cm on this string has a frequency of:
A. 0.0125 Hz B. 0.25 Hz C. 100 Hz
D. 630 Hz E. 2000 Hz
16. When a 100-Hz oscillator is used to generate a sinusoidal wave on a certain string the wavelength
is 10 cm. When the tension in the string is doubled the generator produces a wave with a
frequency and wavelength of:
A. 200 Hz and 20 cm B. 141 Hz and 10 cm C. 100 Hz and 20 cm
D. 100 Hz and 14 cm E. 50 Hz and 14 cm
17. A source of frequency f sends waves f wavelength λ traveling with speed v in some medium. If the
frequency is changed from f to 2f , then the new wavelength and new speed are (respectively):
A. 2λ, v B. λ/2, v C. λ, 2v
D. λ, v/2 E. λ/2, 2v
18. A long string is constructed by joining the ends of two shorter strings. The tension in the strings is
the same but string I has 4 times the linear mass density of string II. When a sinusoidal wave
passes from string I to string II:
A. the frequency decreases by a factor of 4 B. the frequency decreases by a factor of 2
C. the wavelength decreases by a factor of 4 D. the wavelength decreases by a factor of 2
E. the wavelength increases by a factor of 2
19. Three separate strings are made of the same material. String 1 has length L and tension τ , string 2
has length 2L and tension 2τ , and string 3 has length 3L and tension 3τ . A pulse is started at one
end of each string. If the pulses start at the same time, the order in which they reach the other
end is:
A. 1, 2, 3 B. 3, 2, 1 C. 2, 3, 1
D. 3, 1, 2
E. they all take the same time

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The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2
20. A long string is constructed by joining the ends of two shorter strings. The tension in the strings is
the same but string I has 4 times the linear mass density of string II. When a sinusoidal wave
passes from string I to string II:
A. the frequency decreases by a factor of 4 B. the frequency decreases by a factor of 2
C. the wave speed decreases by a factor of 4 D. the wave speed decreases by a factor of 2
E. the wave speed increases by a factor of 2
21. Two identical but separate strings, with the same tension, carry sinusoidal waves with the same
frequency. Wave A has a amplitude that is twice that of wave B and transmits energy at a rate that
is ___________ that of wave B.
A. half B. twice C. one-fourth
D. four times E. eight times
22. Two identical but separate strings, with the same tension, carry sinusoidal waves with the same
frequency. Wave A has an amplitude that is twice that of wave B and transmits energy at a rate
that is _______ that of wave B.
A. half B. twice C. one-fourth
D. four times E. eight times
23. A sinusoidal wave is generated by moving the end of a string up and down periodically. The
generator must supply the greatest power when the end of the string
A. has its greatest acceleration B. has its greatest displacement
C. has half its greatest displacement D. has one-fourth its greatest displacement
E. has its least displacement
24. A sinusoidal wave is generated by moving the end of a string up and down periodically. The
generator does not supply any power when the end of the string
A. has its least acceleration B. has its greatest displacement
C. has half its greatest displacement D. has one-fourth its greatest displacement
E. has its least displacement
25. The sum of two sinusoidal traveling waves is a sinusoidal traveling wave only if:
A. their amplitudes are the same and they travel in the same direction.
B. their amplitudes are the same and they travel in opposite directions.
C. their frequencies are the same and they travel in the same direction.
D. their frequencies are the same and they travel in opposite directions.
E. their frequencies are the same and the r amplitudes are the same.
26. Fully constructive interference between two sinusoidal waves of the same frequency occurs only if
they:
A. travel in opposite directions and are in phase
B. travel in opposite directions and are 180◦ out of phase
C. travel in the same direction and are in phase
D. travel in the same direction and are 180◦ out of phase
E. travel in the same direction and are 90◦ out of phase
27. Fully destructive interference between two sinusoidal waves of the same frequency and amplitude
occurs only if they:
A. travel in opposite directions and are in phase
B. travel in opposite directions and are 180◦ out of phase
C. travel in the same direction and are in phase

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The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2
D. travel in the same direction and are 180◦ out of phase
E. travel in the same direction and are 90◦ out of phase
28. Two separated sources emit sinusoidal traveling waves that have the same wavelength λ and are
in phase at their respective sources. One travels a distance 1 to get to the observation point while
the other travels a distance 2. The amplitude is a minimum at the observation point if 1 − 2 is:
A. an odd multiple of λ/2 B. an odd multiple of λ/4
C. a multiple of λ D. an odd multiple of π/2
E. a multiple of π/3
29. Two separated sources emit sinusoidal traveling waves that have the same wavelength λ and are
in phase at their respective sources. One travels a distance 1 to get to the observation point while
the other travels a distance 2. The amplitude is a maximum at the observation point if 1 − 2 is:
A. an odd multiple of λ/2 B. an odd multiple of λ/4
C. a multiple of λ D. an odd multiple of π/2
E. a multiple of π
30. A wave on a stretched string is reflected from a fixed end P of the string. The phase difference, at
P, between the incident and reflected waves is:
A. zero B. π rad C. π/2 rad
D. depends on the velocity of the wave E. depends on the frequency of the wave
31. A wave on a string is reflected from a fixed end. The reflected wave:
A. is in phase with the original wave at the end
B. is 180◦ out of phase with the original wave at the end
C. has a larger amplitude than the original wave
D. has a larger speed than the original wave E. cannot be transverse
32. A standing wave:
A. can be constructed from two similar waves traveling in opposite directions
B. must be transverse C. must be longitudinal
D. has motionless points that are closer than half a wavelength
E. has a wave velocity that differs by a factor of two from what it would be for a traveling wave
33. When a certain string is clamped at both ends, the lowest four resonant frequencies are 50, 100,
150, and 200 Hz. When the string is also clamped at its midpoint, the lowest four resonant
frequencies are:
A. 50, 100, 150, and 200 Hz B. 50, 150, 250, and 300 Hz
C. 100, 200, 300, and 400 Hz D. 25, 50, 75, and 100 Hz
E. 75, 150, 225, and 300 Hz
34. When a certain string is clamped at both ends, the lowest four resonant frequencies are measured
to be 100, 150, 200, and 250 Hz. One of the resonant frequencies (below 200 Hz) is missing. What
is it?
A. 25 Hz B. 50 Hz C. 75 Hz
D. 125 Hz E. 225 Hz
35. Two traveling waves y1 = A sin[k(x −vt)] and y2 = A sin[k(x + vt)] are superposed on the same
string. The distance between the adjacent nodes is:
A. vt/π B. vt/2π C. π/2k
D. π/k E. 2π/k

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The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2
36. If λ is the wavelength of each of the component sinusoidal traveling waves that form a standing
wave, the distance between adjacent nodes in the standing wave is:
A. λ/4 B. λ/2 C. 3λ/4
D. λ E. 2λ
37. Standing waves are produced by the interference of two traveling sinusoidal waves, each of
frequency 100 Hz. The distance from the second node to the fifth node is 60 cm. The wavelength
of each of the t o original waves is:
A. 50 cm B. 40 cm C. 30 cm
D. 20 cm E. 15 cm
38. A string of length 100 cm is held fixed at both ends and vibrates in a standing wave pattern.
The wavelengths of the constituent traveling waves CANNOT be:
A. 400 cm B. 200 cm C. 100 cm
D. 66.7 cm E. 50 cm
39. A string of length L is clamped at each end and vibrates in a standing wave pattern. The
wavelengths of the constituent traveling waves CANNOT be:
A. L B. 2L C. L/2
D. 2L/3 E. 4L
40. Two sinusoidal waves, each of wavelength 5 m and amplitude 10 cm, travel in opposite directions
on a 20-m long stretched string that is clamped at each end. Excluding the nodes at the ends of
the string, how many nodes appear in the resulting standing wave?
A. 3 B. 4 C. 5
D. 7 E. 8
41. A string, clamped at its ends, vibrates in three segments. The string is 100 cm long. The
wavelength is:
A. 33.3 cm B. 66.7 cm C. 150 cm
D. 300 cm E. need to know the frequency
42. When a string is vibrating in a standing wave pattern the power transmitted across an antinode,
compared to the power transmitted across a node, is:
A. more B. less C. the same (zero)
D. the same (non-zero) E. sometimes more, sometimes less, and sometimes the same
43. A 40-cm long string, with one end clamped and the other free to move transversely, is vibrating in
its fundamental standing wave mode. The wavelength of the constituent traveling waves is:
A. 10 cm B. 20 cm C. 40 cm
D. 80 cm E. 160 cm
44. A 30-cm long string, with one end clamped and the other free to move transversely, is vibrating in
its second harmonic. The wavelength of the constituent traveling waves is:
A. 10 cm B. 30 cm C. 40 cm
D. 60 cm E. 120 cm
45. A 40-cm long string, with one end clamped and the other free to move transversely, is vibrating in
its fundamental standing wave m de. If the wave speed is 320 cm/s the frequency is:
A. 32 Hz B. 16 Hz C. 8 Hz
D. 4 Hz E. 2 Hz

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The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2
46. Five organ pipes are described below. Which one has the highest frequency fundamental?
A. A 2.3-m pipe with one end open and the other closed
B. A 3.3-m pipe with one end open and the other closed
C. A 1.6-m pipe with both ends open
D. A 3.0-m pipe with both ends open
E. A pipe in which the displacement nodes are 5 m apart
47. If the speed of sound is 340 m/s, the length of the shortest closed pipe that resonates at 218 Hz is:
A. 23 cm B. 17 cm C. 39 cm
D. 78 cm E. 1.56 cm
48. The lowest tone produced by a certain organ comes from a 3.0-m pipe with both ends open. If the
speed of sound is 340 m/s, the frequency of this tone is approximately:
A. 7 Hz B. 14 Hz C. 28 Hz
D. 57 Hz E. 70 Hz
49. The speed of sound in air is 340 m/s. The length of the shortest pipe, closed at one end, that will
respond to a 512 Hz tuning fork is approximately:
A. 4.2 cm B. 9.4 cm C. 17 cm
D. 33 cm E. 66 cm
50. If the speed of sound is 340 m/s, the two lowest frequencies of an 0.5-m organ pipe, closed at one
end, are approximately:
A. 170 and 340 Hz B. 170 and 510 Hz C. 340 and 680 Hz
D. 340 and 1020 Hz E. 57 and 170 Hz
51. Organ pipe Y (open at both ends) is half as long as organ pipe X (open at one end) as shown. The
ratio of their fundamental frequencies fX: Y is:
X

Y
A. 1:1 B. 1:2 C. 2:1
D. 1:4 E. 4:1
52. A 200-cm organ pipe with one end open is in resonance with a sound wave of wavelength 270 cm.
The pipe is operating in its:
A. fundamental frequency B. second harmonic
C. third harmonic D. fourth harmonic
E. fifth harmonic
53. An organ pipe with both ends open is 0.85 m long. Assuming that the speed of sound is 340 m/s,
the frequency of the third harmonic of this pipe is:
A. 200 Hz B. 300 Hz C. 400 Hz
D. 600 Hz E. none of these

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The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2
TEST 2
1. The speed of a sound wave is determined by:
A. its amplitude B. its intensity C. its pitch
D. number of harmonics present E. the transmitting medium
2. Take the speed of sound to be 340 m/s. A thunder clap is heard about 3 s after the lightning is
seen. The source of both light and sound is:
A. moving overhead faster than the speed of sound
B. emitting a much higher frequency than is heard
C. emitting a much lower frequency than is heard
D. about 1000 m away E. much more than 1000 m away
3. A sound wave has a wavelength of 3.0 m. The distance from a compression center to the adjacent
rarefaction center is:
A. 0.75 m B. 1.5 m C. 3.0 m
D. need to know wave speed E. need to know frequency
4. A fire whistle emits a tone of 170 Hz. Take the speed of sound in air to be 340 m/s. The
wavelength of this sound is about:
A. 0.5 m B. 1.0 m C. 2.0 m
D. 3.0 m E. 340 m
5. During a time interval of exactly one period of vibration of a tuning fork, the emitted sound travels
a distance:
A. equal to the length of the tuning fork B. equal to twice the length of the tuning fork
C. of about 330 m D. which decreases with time
E. of one wavelength in air
6. At points in a sound wave where the gas is maximally compressed, the pressure
A. is a maximum B. is a minimum C. is equal to the ambient value
D. is greater than the ambient value but less than the maximum
E. is less than the ambient value but greater than the minimum
7. You are listening to an “A” note played on a violin string. Let the subscript “s” refer to the violin
string and “a” refer to the air. Then:
A. fs = fa but λs = λa B. fs = fa and λs = λa C. λs = λa but fs = fa
D. λs = λa and fs = fa E. linear density of string = volume density of air
8. “Beats” in sound refer to:
A. interference of two waves of the same frequency
B. combination of two waves of slightly different frequency
C. reversal of phase of reflected wave relative to incident wave
D. two media having slightly different sound velocities
E. effect of relative motion of source a d observer
9. To produce beats it is necessary to use two waves:
A. traveling in opposite directions B. of slightly different frequencies
C. of equal wavelengths D. of equal amplitudes
E. whose ratio of frequencies is n integer
10. In order for two sound waves to produce audible beats, it is essential that the two waves have:
A. the same amplitude B. the same frequency
C. the same number of harmonics D. slightly different amplitudes

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The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2
E. slightly different frequencies
11. The largest number of beats per second will be heard from which pair of tuning forks?
A. 200 and 201 Hz B. 256 and 260 Hz C. 534 and 540 Hz
D. 763 and 774 Hz E. 8420 and 8422 Hz
12. Two stationary tuning forks (350 and 352 Hz) are struck simultaneously. The resulting sound is
observed to:
A. beat with a frequency of 2 beats/s B. beat with a frequency of 351 beats/s
C. be loud but not beat D. be Doppler shifted by 2 Hz
E. have a frequency of 702 Hz
13. When listening to tuning forks of frequency 256 Hz and 260 Hz, one hears the following number of
beats per second:
A. zero B. 2 C. 4
D. 8 E. 258
14. Two identical tuning forks vibrate at 256 Hz. One of them is then loaded with a drop of wax, after
which 6 beats/s are heard. The period of the loaded tuning fork is:
A. 0.006 s B. 0.005 s C. 0.004 s
D. 0.003 s E. none of these
15. Which of the following properties of a sound wave determine its “pitch”?
A. Amplitude B. Distance from source to detector
C. Frequency D. Phase E. Speed
16. The sound intensity 5.0 m from a point source is 0.50 W/m2. The power output of the source is:
A. 39 W B. 160 W C. 266 W
D. 320 W E. 390 W
17. The standard reference sound level is about:
A. the threshold of human hearing at 1000 Hz
B. the threshold of pain for human hearing at 1000 Hz
C. the level of sound produced when the 1 kg standard mass is dropped 1 m onto a concrete floor
D. the level of normal conversation
E. the level of sound emitted by a standard 60 Hz tuning fork
18. The intensity of sound wave A is 100 times that of sound wave B. Relative to wave B the sound
level of wave A is:
A. −2 db B. +2 db C. +10 db
D. +20 db E. +100 db
19. The intensity of a certain sound wave is 6 µW/cm2. If its intensity is raised by 10 db, the new
intensity (in µW/cm2) is:
A.60 B. 6.6 C. 6.06 D. 600 E. 12
20. If the sound level is increased by 10 db the intensity increases by a factor of:
A. 2 B. 5 C. 10 D. 20 E. 100
21. The sound level at a point P is 14 db below the sound l v l at a point 1.0 m from a point source. The
distance from the source to point P is:
A. 4.0 cm B. 20.2m C. 2.0 m
D. 5.0 m E. 25 m
22. To raise the pitch of a certain piano string, the piano tuner:
A. loosens the string B. tightens the string C. shortens the string

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The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2
D. lengthens the string E. removes some mass
23. A piano wire has length L and mass M. If its fundamental frequency is f, its tension is:
A. 2Lf /m B. 4M Lf C. 2M f2/L
2 3 2
D. 4f L /M E. 4LM f
24. If the length of a piano wire (of given density) is increased by 5%, what approximate change in
tension is necessary to keep its fundamental frequency unchanged?
A. Decrease of 10% B. Decrease of 5% C. Increase of 5%
D. Increase of 10% E. Increase of 20%
25. A piano wire has a length of 81 cm and a mass of 2.0 g. If its fundamental frequency is to be
394Hz, its tension must be:
A. 0.32 N B. 63 N C. 130 N
D. 250 N E. none of these
26. Two identical strings, A and B, have nearly the same tension. When they both vibrate in their
fundamental resonant modes, there is a beat frequency of 3 Hz. When string B is tightened
slightly, to increase the tension, the beat frequency becomes 6 Hz. This means:
A. that before tightening A had a higher frequency than B, but after tightening, B has a higher
frequency than A
B. that before tightening B had a higher frequency than A, but after tightening, A has a higher
frequency than B
C. that before and after tightening A has a higher frequency than B
D. that before and after tightening B has a higher frequency than A
E. none of the above
27. Two pipes are each open at one end and closed at the other. Pipe A has length L and pipe B has
length 2L. Which harmonic of pipe B matches in frequency the fundamental of pipe A?
A. The fundamental B. The second C. The third
D. The fourth E. There are none
28. A column of argon is open at one end and closed at the other. The shortest length of such a
column that will resonate with a 200 Hz tuning fork is 42.5 cm. The speed of sound in argon must
be:
A. 85.0 m/s B. 170 m/s C. 340 m/s
D. 470 m/s E. 940 m/s
29. A tuning fork produces sound waves of wavelength λ in air. This sound is used to cause resonance
in an air column, closed at one end and open at the other. The length of this column CANNOT be:
A. λ/4 B. 2λ/4 C. 3λ/4
D. 5λ/4 E. 7λ/4
30. A 1024 Hz tuning fork is used to obtain a series of resonance levels in a gas column of variable
length, with one end closed and the other open. The length of the column changes by 20 cm from
resonance to resonance. From this data, the speed of sound in this gas is:
A. 20 cm/s B. 51 cm/s C. 102 cm/s
D. 205 m/s E. 410 m/s
31. A vibrating tuning fork is held over a water column with one end closed and the other open. As
the water level is allowed to fall, a loud sound is heard for water levels separated by 17 cm. If the
speed of sound in air is 340 m/s, the frequency of the tuning fork is:
A. 500 Hz B. 1000 Hz C. 2000 Hz

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The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2
D. 5780 Hz E. 578, 000 Hz
32. An organ pipe with one end open and the other closed is operating at one of its resonant
frequencies. The open and closed ends are respectively:
A. pressure node, pressure node B. pressure node, displacement node
C. displacement antinode, pressure node D. displacement node, displacement node
E. pressure antinode, pressure node
33. An organ pipe with one end closed and the other open has length L. Its fundamental frequency is
proportional to:
A. L B. 1/L C. 1/L2
D. L2 E. L3
34. The “A” on a trumpet and a clarinet have the same pitch, but the two are clearly distinguishable.
Which property is most important in enabling one to distinguish between these two instruments?
A. Intensity B. Fundamental frequency
C. Displacement amplitude D. Pressure amplitude
E. Harmonic content
35. The rise in pitch of an approaching siren is an apparent increase in its:
A. speed B. amplitude C. frequency
D. wavelength E. number of harmonics
36. A stationary source generates 5.0 Hz water waves whose speed is 2.0 m/s. A boat is approaching
the source at 10 m/s. The frequency of these waves, as observed by a person in the boat, is:
A. 5.0 Hz B. 15 Hz C. 20 Hz
D. 25 Hz E. 30 Hz
37. A stationary source S generates circular outgoing waves on a lake. The wave speed is 5.0 m/s and
the crest-to-crest distance is 2.0 m. A person in a motor boat heads directly toward S at 3.0 m/s.
To this person, the frequency of these waves is:
A. 1.0 Hz B. 1.5 Hz C. 2.0 Hz
D. 4.0 Hz E. 8.0 Hz
38. A stationary source emits a sound wave of frequency f. If it were possible for a man to travel
toward the source at the speed of sound, he would observe the emitted sound to have a
frequency of:
A. zero B. f /2 C. 2f /3
D. 2f E. infinity
39. A source emits sound with a frequency of 1000 Hz. It and an observer are moving in the same
direction with the same speed, 100 m/s. If the speed of sound is 340 m/s, the observer hears
sound with a frequency of:
A. 294 Hz B. 545 Hz C. 1000 Hz
D. 1830 Hz E. 3400 Hz
40. A source emits sound with a frequency of 1000 Hz. It and an observer are moving toward each
other, each with a speed of 100 m/s. If the speed of sound is 340 m/s, the observer hears sound
with a frequency of:
A. 294 Hz B. 545 Hz C. 1000 Hz
D. 1830 Hz E. 3400 Hz

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The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2
41. A source emits sound with a frequency of 1000 Hz. It is moving at 20 m/s toward a stationary
reflecting wall. If the speed of sound is 340 m/s an observer at rest directly behind the source
hears a beat frequency of:
A. 11 Hz B. 86 Hz C. 97 Hz
D. 118 Hz E. 183 Hz
42. In each of the following two situations a source emits sound with a frequency of 1000 Hz. In
situation I the source is moving at 100 m/s toward an observer at rest. In situation II the observer
is moving at 100 m/s toward the source, which is stationary. The speed of sound is 340 m/s. The
frequencies heard by the observers in the two situations are:
A. I: 1417 Hz; II: 1294 Hz B. I: 1417 Hz; II: 1417 Hz
C. I: 1294 Hz; II: 1294 Hz D. I: 773 Hz; II: 706 Hz
E. I: 773 Hz; II: 773 Hz
43. The Doppler shift formula for the frequency detected is
 v  vo 
f ' = f  
 v  vs 
where f is the frequency emitted, v is the speed of sound, vo is the speed of the detector, and vs is
the speed of the source. Suppose the source is traveling at 5 m/s away from the detector, the
detector is traveling at 7 m/s t ward the source, and there is a 3m/s wind blowing from the source
toward the detector. The values that should be substituted into the Doppler shift equation are:
A. vo = 7 m/s and vs = 5 m/s B. vo = 10 m/s and vs = 8 m/s
C. vo = 4 m/s and vs = 2 m/s D. vo = 10 m/s and vs = 2 m/s
E. vo = 4 m/s and vs = 8 m/s
44. A plane produces a sonic boom only when:
A. it emits sound waves of very long wavelength B. it emits sound waves of high frequency
C. it flies at high altitudes D. it flies on a curved path
E. it flies faster than the speed of sound
45. If the speed of sound is 340 m/s a plane flying at 400 m/s creates a conical shock wave with an
apex half angle of:
A. 0 (no shock wave) B. 32◦ C. 40◦
D. 50◦ E. 58◦
46. The speed of sound is 340 m/s. A plane flies horizontally at an altitude of 10, 000 m and a speed of
400 m/s. When an observer on the ground hears the sonic boom the horizontal distance from the
point on its path directly above the observer to the plane is:
A. 5800 m B. 6200 m C. 8400 m
D. 12, 000 m E. 16, 000 m

Engr. Harish Kumar MDCAT 2025

The SPARK Institute of Language & Sciences
PHYSICS-I WAVE MOTION TEST 1 & 2

ANSWER KEY (TEST 1)

1 A 11 B 21 D 31 B 41 B 51 A

2 B 12 D 22 D 32 A 42 C 52 B

3 D 13 D 23 E 33 C 43 E 53 D

4 B 14 C 24 B 34 B 44 C

5 E 15 C 25 C 35 D 45 E

6 C 16 D 26 C 36 B 46 C

7 E 17 B 27 D 37 B 47 C

8 C 18 D 28 A 38 A 48 D

9 C 19 A 29 C 39 E 49 C

10 D 20 E 30 B 40 D 50 B

ANSWER KEY (TEST 2)

1 E 11 D 21 D 31 B 41 D

2 D 12 A 22 B 32 B 42 A

3 B 13 C 23 E 33 B 43 B

4 C 14 C 24 C 34 E 44 E

5 E 15 C 25 B 35 C 45 E

6 A 16 B 26 D 36 E 46 B

7 A 17 A 27 E 37 D

8 B 18 D 28 C 38 D

9 B 19 A 29 B 39 C

10 E 20 C 30 E 40 D

Engr. Harish Kumar MDCAT 2025