241 + Interview Questions in WAVES-AND-SOUND IN GENERAL AWARENESS Page 3 InterviewSolution

101.	In a sinusoidal wave, the time required for a particular point to move from maximum displacement to zero displacement is 0.170 second. The frequency of the wave isA. 1.47 HzB. 0.36 HzC. 0.73 HzD. 2.94 Hz
Answer» Correct Answer - A

Discussion

102.	The minimum audible wavelength at room temperature is aboutA. ` 0.2 Å`B. `5 Å`C. 5 cm to 2 metreD. 20 mm
Answer» Correct Answer - D

Discussion

103.	In a resonance tube, the first resonance is obtained when the level of water in the tube is at 16 cm from the open end. Neglecting end correction, the next resonance will be obtained when the level of water from the open end isA. `24 cm`B. `32 cm`C. `48 cm`D. `64 cm`
Answer» Correct Answer - C

Discussion

104.	The ratio of the speed of sound in nitrogen gas to that in helium gas, at 300K isA. `sqrt(2//7)`B. `sqrt(1//7)`C. `sqrt(3)//5`D. `sqrt(6)//5`
Answer» Correct Answer - C

Discussion

105.	The length of two open organ pipes are `l` and `(l+deltal)` respectively. Neglecting end correction, the frequency of beats between them will b approximately.A. `v/(2l)`B. `v/(4l)`C. `(v Deltal)/(2l^(2))`D. `(vDelta l)/(l)`
Answer» Correct Answer - C

Discussion

106.	A source of sound emits 200`piW` power which is uniformly distributed over a sphere of radius 10 m. What is the loudness of sound on the surface of the sphere?A. `200 dB`B. `200 pi dB`C. `120 dB`D. `120 pi dB`
Answer» Correct Answer - C

Discussion

107.	Velocity of sound measured in hydrogen and oxygen gas at a given temperature will be in the ratioA. ` 1 : 4`B. ` 4 : 1`C. `2 : 1`D. `1 :1`
Answer» Correct Answer - B

Discussion

108.	At which temperature the speed of sound in hydrogen will be same as that of speed of sound in oxygen at 100o C [A. `-148^(@)C`B. `-212.5^(@)C`C. `317.5^(@)C`D. `-249.7^(@)C`
Answer» Correct Answer - D

Discussion

109.	The wave length of light in visible part `(lambda_(v))` and for sound `(lambda_(s))` are related asA. `lambda_(v) gt lambda_(s)`B. `lambda_(s) gt lambda_(v)`C. `lambda_(v) = lambda_(s)`D. None of these
Answer» Correct Answer - B

Discussion

110.	When a tuning fork vibrates, the waves produced in the fork areA. LongitudinalB. TransverseC. ProgressiveD. Stationary
Answer» Correct Answer - A

Discussion

111.	When a tuning fork produces sound waves in air, which one of the following is same in the material of tuning fork as well as in airA. WavelengthB. FrequencyC. VelocityD. Amplitude
Answer» Correct Answer - B

Discussion

112.	A tuning fork produces waves in a medium. If the temperature of the medium changes, then which of the following will changeA. AmplitudeB. FrequencyC. WavelengthD. Time-period
Answer» Correct Answer - C

Discussion

113.	In Melde’s experiment in the transverse mode, the frequency of the tuning fork and the frequency of the waves in the strings are in the ratioA. `1:1`B. `1:2`C. `2:1`D. `4:1`
Answer» Correct Answer - A

Discussion

114.	Three similar wires of frequency `n_(1),n_(2)` and `n_(3)` are joined to make one wire. Its frequency will beA. `n=n_(1)+n_(2)+n_(3)`B. `1/n=1/(n_(1))+1/(n_(2))+1/(n_(3))`C. `1/(sqrt(n))=1/(sqrt(n_(1)))+1/(sqrt(n_(2)))+1/(sqrt(n_(3)))`D. `1/(n^(1))=1/(n_(1)^(2))+1/(n_(2)^(2))+1/(n_(3)^(2))`
Answer» Correct Answer - B

Discussion

115.	The frequency of transverse vibrations in a stretched string is 200 Hz . If the tension is increased four times and the length is reduced to one-fourth the original value, the frequency of vibration will beA. 25 HzB. 200 HzC. 400 HzD. 1600 Hz
Answer» Correct Answer - D

Discussion

116.	The tension of a stretched string is increased by 69%. In order to keep its frequency of vibration constant, its length must be increased by :A. 0.2B. 0.3C. `sqrt(69) %`D. 0.69
Answer» Correct Answer - B

Discussion

117.	Learned Indian classical vocalists do not like the accompaniment of a harmonium becauseA. Intensity of the notes of the harmonium is too largeB. Notes of the harmonium are too shrillC. Diatonic scale is used in the harmoniumD. Tempered scale is used in the harmonium
Answer» Correct Answer - D

Discussion

118.	Two sources of sound `A` and `B` produces the wave of `350 Hz`. They vibrate in the same phase. The particel `P` is vibrating under the influence of these two waves, if the amplitudes at the point P produced by the two waves is `0.3mm` and `0.4mm` then the resultant amplitude of the point `P` will be when `AP-BP=25cm` and the velocity of sound is `350m//sec`.A. `0.7 mm`B. `0.1 mm`C. `0.2 mm`D. `0.5 mm`
Answer» Correct Answer - D

Discussion

119.	Which of the following is not true for the progressive wave `y=4sin2pi((t)/(0.02)-(x)/(100))` where x and y are in cm and t in seconds.A. Its amplitude is 4 cmB. Its wavelength is 100 cmC. Its frequency is 50 cycles/secD. Its propagation velocity is ` 50 xx 10^(3)` cm /sec
Answer» Correct Answer - D

Discussion

120.	A simple harmonic progressive wave is representive by the equation `y=8 sin 2pi (0.1x -2t)` where x and y are in centimetres and t is in seconds. At any instant the phase difference between two particle separted by 2.0 cm along the x-direction isA. 18B. 36C. 54D. 72
Answer» Correct Answer - D

Discussion

121.	The equation of a progressive wave is given by `y=a sin (628 t-31.4 x)` If the distances are expressed in cms and time in seconds, then the wave velocity will beA. 314 cm/secB. 628 cm/secC. 20 cm/secD. 400 cm/sec
Answer» Correct Answer - C

Discussion

122.	A wave disturbance in a medium is described by `y(x,t) = 0.02 "cos"(50pit + (pi)/(2))"cos"(10pix)` where x and y are in metre and t is in second . Which of the following is correct ?A. A displacement node occurs at x = 0.15 mB. An antinode occurs at `x = 0.3 m`C. The wavelength of the wave is 0.2 mD. The speed of the wave is 5.0 m/s
Answer» Correct Answer - A::B::C::D

Discussion

123.	A man is watching two trains, one leaving and the other coming in with equal speed of 4 m/s. If they sound their whistles, each of frequency 240 Hz, the number of beats heard by the man (velocity of sound in air is `320(m)/(s)`) will be equal toA. 6B. 3C. 0D. 12
Answer» Correct Answer - A

Discussion

124.	A wire of density `9 xx 10^(3) kg//m^(3)` is stretched between two clamps 1 m apart and is subjected to an extension of `4.9 xx 10^(-4) m`. The lowest frequency of transverse vibration in the wire is `(Y = 9 xx 10^(10) N//m^(2))`A. `40 Hz`B. `35 Hz`C. `30 Hz`D. `25 Hz`
Answer» Correct Answer - B

Discussion

125.	A transverse sinusoidal wave of amplitude `a`, wavelength `lambda` and frequency `f` is travelling on a stretched string. The maximum speed of any point in the string is `v//10`, where `v` is the speed of propagation of the wave. If `a = 10^(-3)m` and `v = 10ms^(-1)`, then `lambda` and `f` are given byA. `lambda= 2 pi xx 10^(-2)m`B. `lambda = 10^(-3) m`C. `n=(10)^(3)/(2pi) Hz`D. `n=10^(4) Hz`
Answer» Correct Answer - A::C

Discussion

126.	With what velocity an observer sould move relative to a stationary source so that he hears a sound of double the frequency of souce?A. Velocity of sound towards the sourceB. Velocity of sound away from the sourceC. Half the velocity of sound towards the sourceD. Double the velocity of sound towards the source
Answer» Correct Answer - A

Discussion

127.	A source and an observer move away from each other with a velocity of 10 m/s with respect to ground. If the observer finds the frequency of sound coming from the source as 1950 Hz , then actual frequency of the source is (velocity of sound in air = 340 m/s )A. 1950 HzB. 2068 HzC. 2132 HzD. 2486 Hz
Answer» Correct Answer - B

Discussion

128.	At what speed should a source of sound move so that stationary observer finds the apparent frequency equal to half of the original frequencyA. `v/2`B. `2v`C. `v/4`D. `v`
Answer» Correct Answer - D

Discussion

129.	A sound spurce is moving towards a stationary observer with 1/10 of the speed of sound. The ratio of apparent to real frequency isA. `10//9`B. `11//10`C. `(11//10)^(2)`D. `(9//10)^(2)`
Answer» Correct Answer - A

Discussion

130.	Stationary waves are produced in 10 m long stretched string. If the string vibrates in 5 segments and wave velocity 20 m/s then the frequency is :-A. 2HzB. 4HzC. 5 HzD. 10 Hz
Answer» Correct Answer - C

Discussion

131.	A string fixed at both the ends is vibrating in two segments. The wavelength of the corresponding wave isA. `l/4`B. `l/2`C. lD. 2l
Answer» Correct Answer - C

Discussion

132.	A 1 cm long string vibrates with fundamental frequency of 256 Hz . If the length is reduced to `1/4` cm keeping the tension unaltered, thenew fundamental frequency will beA. 64B. 256C. 512D. 1024
Answer» Correct Answer - D

Discussion

133.	Four wires of identical lengths, diameters and materials are stretched on a sonometer box. The ratio of their tension `1:4:9:16`. The ratio of their fundamental frequencies isA. `16:9:4:1`B. `4:3:2:1`C. `1:4:2:16`D. `1:2:3:4`
Answer» Correct Answer - D

Discussion

134.	It is desired to increase the fundamental resonance frequency in a tube which is closed at one end. This can be achieved byA. Replacing the air in the tube by hydrogen gasB. Increasing the length of the tubeC. Decreasing the length of the tubeD. Opening the closed end of the tube
Answer» Correct Answer - A::C::D

Discussion

135.	The frequency of a stretched uniform wire under tension is in resonance with the fundamental frequency of a closed tube. If the tension in the wire is increased by 8 N , it is in resonance with the first overtone of the closed tube. The initial tension in the wire isA. 1NB. 4NC. 8ND. 16 N
Answer» Correct Answer - A

Discussion

136.	The fundamental frequency of a sonometre wire is n . If its radius is doubled and its tension becomes half, the material of the wire remains same, the new fundamental frequency will beA. nB. `n/(sqrt(2))`C. `n/2`D. `n/(2sqrt(2))`
Answer» Correct Answer - D

Discussion

137.	The intensity of sound increases at night due toA. Increase in density of airB. Decreases in density of airC. Low temperatureD. None of these
Answer» Correct Answer - A

Discussion

138.	Sound travels in rocks in the form of :A. Longitudinal elastic waves onlyB. Transverse elastic waves onlyC. Both longitudinal and transverse elastic wavesD. Non-elastic waves
Answer» Correct Answer - C

Discussion

139.	Assertion : When we start filling an empty bucket with water, the pitch of sound produced goes on decreasing. Reason : The frequency of man voice is usually higher than of woman.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but re ason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If the assertion and reason both are false.
Answer» Correct Answer - D

Discussion

140.	Which of the following is the longitudinal waveA. Sound wavesB. Waves on plucked stringC. Water wavesD. Light waves
Answer» Correct Answer - A

Discussion

141.	In the musical octave ‘Sa’, ‘Re’, ‘Ga’A. The frequency of the note ‘Sa’ is greater than that of ‘Re’, ‘Ga’B. The frequency of the note ‘Sa’ is smaller than that of ‘Re’, ‘Ga’C. The frequency of all the notes ‘Sa’, ‘Re’, ‘Ga’ is the sameD. The frequency decreases in the sequence ‘Sa’, ‘Re’, ‘Ga’
Answer» Correct Answer - B

Discussion

142.	Of the following, the one which emits sound of higher pitch is :A. MosquitoB. LionC. ManD. Woman
Answer» Correct Answer - A

Discussion

143.	Stationary waves are formed whenA. Two waves of equal amplitude and equal frequency travel along the same path in opposite directionsB. Two waves of equal wavelength and equal amplitude travel along the same path with equal speeds in opposite directionsC. Two waves of equal wavelength and equal phase travel along the same path with equal speedD. Two waves of equal amplitude and equal speed travel along the same path in opposite direction
Answer» Correct Answer - B

Discussion

144.	Which of the property makes difference between progressive and stationary wavesA. AmplitudeB. FrequencyC. Propagation of energyD. Phase of the wave
Answer» Correct Answer - C

Discussion

145.	To increase the frequency from 100 Hz to 400 Hz the tension in the string has to be changed byA. 4 timesB. 16 timesC. 20 timesD. None of these
Answer» Correct Answer - B

Discussion

146.	A string on a musical instrument is 50 cm long and its fundamental frequency is 270 Hz. If the desired frequency of 1000 Hz, is to be produced, the required length of the string isA. 13.5 cmB. 2.7 cmC. 5.4 cmD. 10.3 cm
Answer» Correct Answer - A

Discussion

147.	The tension in a piano wire is `10 N`. The tension ina piano wire to produce a node of double frequency isA. 5NB. 20 NC. 40 ND. 80 N
Answer» Correct Answer - C

Discussion

148.	Two adjacent piano keys are struck simultaneously. The notes emitted by them have frequencies `n_(1) and n_(2)` . The number of beats heard per second isA. `(1)/(2) (n_(1)-n_(2))`B. `(1)/(2) (n_(1)+n_(2))`C. `n_(1) ~ n_(2)`D. `2 (n_(1)-n_(2))`
Answer» Correct Answer - C

Discussion

149.	What will be the wave velocity, if the radar gives 54 waves per min and wavelength of the given wave is 10 mA. `4//sec`B. `6 m//sec`C. `9 m //sec`D. `5 m//sec`
Answer» Correct Answer - C

Discussion

150.	A man stands in front of a hillock and fires a gun. He hears an echo after 1.5 sec . The distance of the hillock from the man is (velocity of sound in air is 330 m/s )A. 220 mB. 247.5 mC. 268.5 mD. 292.5 m
Answer» Correct Answer - B

Discussion

Explore topic-wise InterviewSolutions in .

In a sinusoidal wave, the time required for a particular point to move from maximum displacement to zero displacement is 0.170 second. The frequency of the wave isA. 1.47 HzB. 0.36 HzC. 0.73 HzD. 2.94 Hz

The minimum audible wavelength at room temperature is aboutA. ` 0.2 Å`B. `5 Å`C. 5 cm to 2 metreD. 20 mm

In a resonance tube, the first resonance is obtained when the level of water in the tube is at 16 cm from the open end. Neglecting end correction, the next resonance will be obtained when the level of water from the open end isA. `24 cm`B. `32 cm`C. `48 cm`D. `64 cm`

The ratio of the speed of sound in nitrogen gas to that in helium gas, at 300K isA. `sqrt(2//7)`B. `sqrt(1//7)`C. `sqrt(3)//5`D. `sqrt(6)//5`

The length of two open organ pipes are `l` and `(l+deltal)` respectively. Neglecting end correction, the frequency of beats between them will b approximately.A. `v/(2l)`B. `v/(4l)`C. `(v Deltal)/(2l^(2))`D. `(vDelta l)/(l)`

A source of sound emits 200`piW` power which is uniformly distributed over a sphere of radius 10 m. What is the loudness of sound on the surface of the sphere?A. `200 dB`B. `200 pi dB`C. `120 dB`D. `120 pi dB`

Velocity of sound measured in hydrogen and oxygen gas at a given temperature will be in the ratioA. ` 1 : 4`B. ` 4 : 1`C. `2 : 1`D. `1 :1`

At which temperature the speed of sound in hydrogen will be same as that of speed of sound in oxygen at 100o C [A. `-148^(@)C`B. `-212.5^(@)C`C. `317.5^(@)C`D. `-249.7^(@)C`

The wave length of light in visible part `(lambda_(v))` and for sound `(lambda_(s))` are related asA. `lambda_(v) gt lambda_(s)`B. `lambda_(s) gt lambda_(v)`C. `lambda_(v) = lambda_(s)`D. None of these

When a tuning fork vibrates, the waves produced in the fork areA. LongitudinalB. TransverseC. ProgressiveD. Stationary

When a tuning fork produces sound waves in air, which one of the following is same in the material of tuning fork as well as in airA. WavelengthB. FrequencyC. VelocityD. Amplitude

A tuning fork produces waves in a medium. If the temperature of the medium changes, then which of the following will changeA. AmplitudeB. FrequencyC. WavelengthD. Time-period

In Melde’s experiment in the transverse mode, the frequency of the tuning fork and the frequency of the waves in the strings are in the ratioA. `1:1`B. `1:2`C. `2:1`D. `4:1`

Three similar wires of frequency `n_(1),n_(2)` and `n_(3)` are joined to make one wire. Its frequency will beA. `n=n_(1)+n_(2)+n_(3)`B. `1/n=1/(n_(1))+1/(n_(2))+1/(n_(3))`C. `1/(sqrt(n))=1/(sqrt(n_(1)))+1/(sqrt(n_(2)))+1/(sqrt(n_(3)))`D. `1/(n^(1))=1/(n_(1)^(2))+1/(n_(2)^(2))+1/(n_(3)^(2))`

The frequency of transverse vibrations in a stretched string is 200 Hz . If the tension is increased four times and the length is reduced to one-fourth the original value, the frequency of vibration will beA. 25 HzB. 200 HzC. 400 HzD. 1600 Hz

The tension of a stretched string is increased by 69%. In order to keep its frequency of vibration constant, its length must be increased by :A. 0.2B. 0.3C. `sqrt(69) %`D. 0.69

Learned Indian classical vocalists do not like the accompaniment of a harmonium becauseA. Intensity of the notes of the harmonium is too largeB. Notes of the harmonium are too shrillC. Diatonic scale is used in the harmoniumD. Tempered scale is used in the harmonium

Which of the following is not true for the progressive wave `y=4sin2pi((t)/(0.02)-(x)/(100))` where x and y are in cm and t in seconds.A. Its amplitude is 4 cmB. Its wavelength is 100 cmC. Its frequency is 50 cycles/secD. Its propagation velocity is ` 50 xx 10^(3)` cm /sec

A simple harmonic progressive wave is representive by the equation `y=8 sin 2pi (0.1x -2t)` where x and y are in centimetres and t is in seconds. At any instant the phase difference between two particle separted by 2.0 cm along the x-direction isA. 18B. 36C. 54D. 72

The equation of a progressive wave is given by `y=a sin (628 t-31.4 x)` If the distances are expressed in cms and time in seconds, then the wave velocity will beA. 314 cm/secB. 628 cm/secC. 20 cm/secD. 400 cm/sec

A man is watching two trains, one leaving and the other coming in with equal speed of 4 m/s. If they sound their whistles, each of frequency 240 Hz, the number of beats heard by the man (velocity of sound in air is `320(m)/(s)`) will be equal toA. 6B. 3C. 0D. 12

A wire of density `9 xx 10^(3) kg//m^(3)` is stretched between two clamps 1 m apart and is subjected to an extension of `4.9 xx 10^(-4) m`. The lowest frequency of transverse vibration in the wire is `(Y = 9 xx 10^(10) N//m^(2))`A. `40 Hz`B. `35 Hz`C. `30 Hz`D. `25 Hz`

A source and an observer move away from each other with a velocity of 10 m/s with respect to ground. If the observer finds the frequency of sound coming from the source as 1950 Hz , then actual frequency of the source is (velocity of sound in air = 340 m/s )A. 1950 HzB. 2068 HzC. 2132 HzD. 2486 Hz

At what speed should a source of sound move so that stationary observer finds the apparent frequency equal to half of the original frequencyA. `v/2`B. `2v`C. `v/4`D. `v`

A sound spurce is moving towards a stationary observer with 1/10 of the speed of sound. The ratio of apparent to real frequency isA. `10//9`B. `11//10`C. `(11//10)^(2)`D. `(9//10)^(2)`

Stationary waves are produced in 10 m long stretched string. If the string vibrates in 5 segments and wave velocity 20 m/s then the frequency is :-A. 2HzB. 4HzC. 5 HzD. 10 Hz

A string fixed at both the ends is vibrating in two segments. The wavelength of the corresponding wave isA. `l/4`B. `l/2`C. lD. 2l

A 1 cm long string vibrates with fundamental frequency of 256 Hz . If the length is reduced to `1/4` cm keeping the tension unaltered, thenew fundamental frequency will beA. 64B. 256C. 512D. 1024

Four wires of identical lengths, diameters and materials are stretched on a sonometer box. The ratio of their tension `1:4:9:16`. The ratio of their fundamental frequencies isA. `16:9:4:1`B. `4:3:2:1`C. `1:4:2:16`D. `1:2:3:4`

It is desired to increase the fundamental resonance frequency in a tube which is closed at one end. This can be achieved byA. Replacing the air in the tube by hydrogen gasB. Increasing the length of the tubeC. Decreasing the length of the tubeD. Opening the closed end of the tube

The frequency of a stretched uniform wire under tension is in resonance with the fundamental frequency of a closed tube. If the tension in the wire is increased by 8 N , it is in resonance with the first overtone of the closed tube. The initial tension in the wire isA. 1NB. 4NC. 8ND. 16 N

The fundamental frequency of a sonometre wire is n . If its radius is doubled and its tension becomes half, the material of the wire remains same, the new fundamental frequency will beA. nB. `n/(sqrt(2))`C. `n/2`D. `n/(2sqrt(2))`

The intensity of sound increases at night due toA. Increase in density of airB. Decreases in density of airC. Low temperatureD. None of these

Sound travels in rocks in the form of :A. Longitudinal elastic waves onlyB. Transverse elastic waves onlyC. Both longitudinal and transverse elastic wavesD. Non-elastic waves

Which of the following is the longitudinal waveA. Sound wavesB. Waves on plucked stringC. Water wavesD. Light waves

Of the following, the one which emits sound of higher pitch is :A. MosquitoB. LionC. ManD. Woman

Which of the property makes difference between progressive and stationary wavesA. AmplitudeB. FrequencyC. Propagation of energyD. Phase of the wave

To increase the frequency from 100 Hz to 400 Hz the tension in the string has to be changed byA. 4 timesB. 16 timesC. 20 timesD. None of these

A string on a musical instrument is 50 cm long and its fundamental frequency is 270 Hz. If the desired frequency of 1000 Hz, is to be produced, the required length of the string isA. 13.5 cmB. 2.7 cmC. 5.4 cmD. 10.3 cm

The tension in a piano wire is `10 N`. The tension ina piano wire to produce a node of double frequency isA. 5NB. 20 NC. 40 ND. 80 N

Two adjacent piano keys are struck simultaneously. The notes emitted by them have frequencies `n_(1) and n_(2)` . The number of beats heard per second isA. `(1)/(2) (n_(1)-n_(2))`B. `(1)/(2) (n_(1)+n_(2))`C. `n_(1) ~ n_(2)`D. `2 (n_(1)-n_(2))`

What will be the wave velocity, if the radar gives 54 waves per min and wavelength of the given wave is 10 mA. `4//sec`B. `6 m//sec`C. `9 m //sec`D. `5 m//sec`

A man stands in front of a hillock and fires a gun. He hears an echo after 1.5 sec . The distance of the hillock from the man is (velocity of sound in air is 330 m/s )A. 220 mB. 247.5 mC. 268.5 mD. 292.5 m