WorksheetsNUMS T4 Waves
Total questions: 50
Worksheet time: 57mins
Theoretical value of speed of sound is
300 m/s
248 m/s
332 m/s
All of these
At points in a sound wave where the gas is maximally compressed, the pressure
Is a minimum
Is equal to the ambient value
Is a maximum
None of these
With the propagation of a longitudinal wave through a material medium, the quantities transferred in the direction of propagation are
Energy, momentum and mass
Energy and mass
Energy and momentum
Energy
How does the speed v of sound in air depend on the atmospheric pressure P?
Direct
inverse
independent
none of these
At what temperature the speed of sound in air will be 1.5 times its value at 27°C in air?
102°C
204°C
402°C
None of these
When sound waves enter from air into water, then
λ increases
Frequency increases
Speed decreases
All of them
ultrasonic scanner is used in a hospital to detect tumour in tissue. The working frequency of the scanner is 4.2 mega Hz. The velocity of sound in the tissue is 2.1 km/s. The wavelength of sound in the tissue is nearest to
4 × 10-3m
5 × 10-4m
8 × 10-3m
8 × 10-4m
The percentage error in Newton’s formula for the speed of sound in air is
15%
20%
16%
10%
The speed of a sinusoidal wave on a string depends on:
The tension in the string
The length of the string
The frequency of the wave
The wavelength of the wave
sound waves during the compressions
Density of medium is maximum
Density of the medium is minimum
Pressure of medium is maximum
Both ‘A’ and ‘C’
particular wavelength received from a galaxy is measured on earth and is found to be 5% more then that its’ wave length. Hence galaxy is
Moving towards earth
Stationary with respect to earth
Going away from earth
None of these
The sum of two sinusoidal traveling waves is a sinusoidal traveling wave only if:
Their frequencies are the same and they travel in the same direction
Their frequencies are the same and they travel in opposite directions
Their amplitudes are the same and they travel in opposite directions.
Their amplitudes are the same and they travel in the same direction
A standing wave:
Has motionless points that are closer than half a wavelength
Must be longitudinal
Can be constructed from two similar waves traveling in opposite directions
Must be transverse
The speed of sound in vacuum at 10°C is
338.2 m/s
332 m/s
340 m/s
0 m/s
With rise in temperature, the speed of sound in a gas
Increases
Decreases
Remains same
May increase or decrease depending upon air pressure
Which of the following is mechanical wave?
Light waves
X-rays
Sound waves
Radio waves
To produce beats it is necessary to use two waves:
Of equal amplitudes
Of equal wavelengths
of same frequencies
of slightly different frequencies
On decreasing the temperature, the frequency of an organ pipe becomes
Decrease
Equal
Increase
Infinity
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:
λ/4
2λ/4
3λ/4
5λ/4
A sitar wire vibrates with frequency of 330 vibrations per second. If its length is increased three times and tension is increased four times, then the frequency of the wire will be
110 Hz
330 Hz
220 Hz
440 Hz
The length of a string is 1m, tension in it is 40N and mass of the string is 0.1 kg. Then the velocity of transverse waves produced in the string will be
400 m/s
80 m/s
180 m/s
20 m/s
The length of a string is 1m, tension in it is 40N and mass of the string is 0.1 kg. Then the velocity of transverse waves produced in the string will be
400 m/s
80 m/s
180 m/s
20 m/s
A tube closed at one end and containing air produce fundamental note of frequency of 256 Hz. If the tube is open at both ends, the fundamental frequency will be:
512 Hz
128 Hz
384 Hz
64 Hz
When both source and listener move in the same direction with a velocity equal to half the velocity of sound, the change in frequency of the sound as detected by the listener is:
50%
Zero
25%
None of these
The wavelength of the produced by a source is 0.8m. If the source moves towards the stationary listener at 32 m/s, what will be apparent wavelength of the sound? The velocity of sound is 320 m/s
0.80 m
0.40 m
0.72 m
0.32 m
A plane produces a sonic boom only when
It emits sound waves of very long wavelength
It emits sound waves of high frequency
It flys faster than the speed of sound
It flys on a curved path
The speed of a sound wave is determined by:
The transmitting medium
Number of harmonics present
Its intensity
Its amplitude
If a stretched-string is 4m and it has 4 loops of stationary waves, then wave length is
1m
2m
3m
4m
In resonance tube, which of the followings is formed at open end
Node
Antinodes
Neither A nor B
Either A or B
The frequency of the fundamental mode of transverse vibration of a stretched wire 1000 mm long is 250 Hz. When the wire is shortened to 500 mm at the same tension, what is the fundamental frequency?
125 Hz
250 Hz
500 Hz
1000 Hz
If the speed of sound on a cold day is vc and its speed on hot day is va then
vc = va
vc < va
vc > va
vc may be more or less than va
A stretched string resonates with fundamental frequency of 50 Hz. The wavelength for its 3rd overtone is if speed of transverse wave in the string is 100 m/s
66 cm
33 cm
50 cm
100 cm
The ratio of 2nd overtone to 3rd overtone in stationary wave produced in an air column open at both ends is
4/3
2/3
3/4
1/2
Frequency f and angular frequency ω are related by
f = πω
f = ω/2π
f = ω/π
f = 2πω
A source of frequency "f' sends waves of 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):
2λ, V
λ, 2V
λ/2, V
λ, V/2
The speed of stationary waves in a stretched string are independent of
Number of loops
Tension in the string
Point where string is plucked
Both (a) and (c)
Increase in velocity of sound in the air for 1°C rise in temperature is
1.61 ms-1
61.0 ms-1
0.61ms-1
2.00ms-1
Newton assumed that sound propagation in a gas takes place under:
Isothermal condition
Adiabatic condition
Isobaric condition
Isochoric condition
.The velocity of sound in air would become double than its velocity at 0°C at temperature
313°C
586°C
819°C
1172°C
At what temperature, the velocity of sound will be double its value at 273 K?
2 x 273 K
4 x 273 K
8 x 273 K
16 x 273 K
what temperature the speed of sound in air is 1.5 times than its value at 27 °C ?
102 °C
204 °C
204 K
402 °C
A point source of sound emits energy in all directions at a constant rate and a person 8 m from the source listens. After a while, the intensity of the source is doubled. If the person wishes the sound to seem as loud as before, how far should he be now from the source?
4 m
16 m
8√2 m
16√2 m
Temperature of air is increased from 0 °C to 273 °C, if density of air is increased from ρo to ρt then ratio ρt/ρo is equal to:
1
2
1/2
4
A sound wave is passing through an air column. During the consequent compressions and rarefactions:
Boyle’s law is obeyed
Density of air remains constant
Bulk modulus of air oscillates
Total amount of heat remains constant
The speed of sound in hydrogen is time than that in oxygen
two times
three times
four time
six time
Which of the following has maximum value of γ=Cp/Cv ?
Monoatomic gas
Diatomic gas
Polyatomic gas
All have same value
The speed of sound waves having a frequency of 256 Hz, compared with the speed of sound waves having a frequency of 512 Hz is:
Half as great
Twice as great
Four times as great
Same
Due to overlapping of two identical waves the speed of resultant wave
Decrease
Becomes velocity
Increase
Remains same
When two identical traveling waves are superimposed, the velocity of the resultant wave
Decreases
Increases
Remains unchanged
Becomes zero
A phase angle of 180° is equivalent to the path difference of:
λ/4
λ
λ/2
2λ
