Page 1 :
NCERTExemplar MCQs, 1., , Water waves produced by a motorboat, (a) neither longitudinal nor transvers, , sailingi1in water are, , 4., , b) both longitudinal and transverse, , (c) only longitudinal, , 2, 3, , of wavelength, , A travelling in a medium with a, another, medium where its speed in, m/s, enter, into, ofv, speed, 2v m/s. Wavelength gfsound waves in the second medium is, waves, , (6), , (a), , Speed, , (c), , 2, , of sound wavé in air, , (a) is independent oftemperature, (b), , increases with pressure, , (d), , ()wavelength of sound, , (d) only transverse, Sound, , (c) increases with increase in humidity, decreases with increase in humidity, Change in temperature ofthe medium changes, (a) frequency of sound waves, (b) amplitude of sound waves, , (d), , 41, , (d), , 5., , loudness of sound, , waves, , waves, , With propagation of longitudinal wavesthrough a medium., the quantity transmitted is, (a) matter, , (b) energy, (c) energy and matter, (d) energy,, , matter and momentumn

Page 2 :
6., , Which of the following statements are true for wave motion?, (a) Mechanical transverse waves can propagate through, , 12., , all mediums., , (b) Longitudinal waves can propagate through solids only., (c) Mechanical transverse waves can propagate through, , solids only., (d) Longitudinal waves can propagate through vacuum., 7., , 3., , 2 mm, the number of beats/sec. will be, (c) 2, (b), (a) 4, 13., , y, , =, , 0.6sin 2, , AIIMS 2014, C, , (b) 30 ms-, , 300 m s-, , (a), 14., , (d), , 40 ms-l, , Assertion : Doppler formula for sound wave is symmetrie, with respect to the speed of source and speed of observer., , Reason Motion of source with respect to stationary, observer is not equivalent to the motion ofan observer with, , 2, its amplitude becomes o f the amplitude of the incident, , respect to stationary source., , wave. The equation of the reflected wave is, , (a), , ofmass, , (b), , (c) If Assertion is correct but Reason is incorrect., 15., , 200N=T, , (a) 1s, (b) 0.5 s, , 16., , -20 m-, , (c)2s, d) data given is insufficient, , A train whistling at constant frequency is moving towards a, station at a constant speed v. The train goes past a stationary, , If both Assertion and Reason are correct, but Reason, , is not the correct explanation of Assertion., , of 200, , struck at one end of the string, the disturbance will reach the, , (d) If both the Assertion and Reason are incorrect., A pipe of length 85 cm is closed from one end. Find the, number of possible natural oscillations ofair column in the, pipe whose frequencies lie below 1250 Hz. The velocity of, sound in air is 340 m/s., JEE Main 2014, C], (a) 12, (b)8, (d) 4, c)6, When the wavelength ofsound changes from I mto 1.01 m,, the number of beats heard are 4. The velocity of Sound is, , (BITSAT 2014, C], (a) 404 m/s (b) 4.04m/s (c) 414 m/s (d) 400 m/s, 17., , observer on the station. The frequencyn' of the sound as, heard by the observer is plotted as a function of time, , A source of sound S emitting waves of frequency 100 Hz, and an observor O are located at some distance from each, , other. The source is moving with a speed of 19.4 ms' at an, angle of 60° with the source observer line as shown in the, figure. The observor is at rest. The apparent frequency, by the observer is (velocity of sound in air, , (figure). Identify the expected curve., , observed, , a), , 330 ms, , (b), , (b), , 103 Hz, 106 Hz, , (c), , 97 Hz, , (a), nA, , n, , (c), , A, , (d), , (d), , 18., , slows down to 36 km/hour. He finds that traffic has eased, and a car moving ahead of him at 18 km/hour is honking at a, frequency of 1392 Hz. Ifthe speeds of sound is 343 m/s, the, honk as heard by him will be:, frequency, , 1332 Hz b), , [AIPMT 2014, A], , 1372 Hz (c), , 60, , 100 Hz, A string is stretched between two fixed, points separated by, 75.0 cm. It is observed to have resonant frequencies, of 420, Hz and 315 Hz. There are no other resonant, frequencies, , string is, , A speeding motorcyclist sees trafic jam ahead of him. He, , (a), , AIPMT 2015, A], , between these two. The lowest resonant frequency for this, , Past Year MCQs, , ofthe, , LAIIMS 2014, C], , If both Assertion and Reason are correct and Reason, , is the correct explanation of Assertion., , (b) =-0.4sin27|, , other end in, , 10., , 0.30, , (c) 400 m s-l, , a, , A string, 2.5 kg is under tension, N. The length, of the stretched string is 20.0 m. If the transverse jerk is, , 3, , Here x andy are in metre and t is in second. The velocity of, , y=0.4 sin 27|1+(d) V=-0.4sin 27, 9., , (d), , x, 0.01, , propagation of the wave is, , |. On reflection from denser medium, , (a) y=0.6sin, sin2m|, , lAIIMS 2014, C, , The equation of a progressive wave is, , y=0.02 sin 2, , A sound wave is passing through air column in the form of, compression and rarefaction. In consecutive compressions, , and rarefactions,, (a) density remains constant, (b) Boyle's law is obeyed, (c) bulk modulus of air oscillates, (d) there is no transfer of heat, Equation of a plane progressive wave is given by, , A fork offrequency 256 Hz resonates with a closed organ, pipe oflength 25.4 cm. Ifthe length of pipe be increased by, , 1412 Hz (d), , 1464 Hz, , 19., , [AIPMT 2015, C], , (a) 205 Hz (b) 10.5 Hz (c) 105 Hz (d) 155 Hz, Two waves of wavelengths 99 cm and 100 cm both, travelling, with velocity 396 m/s are made to interfere. The number of, beats produced by them per second is, , (a), (c), , (b), 4, , 2, , (d)8, , [AIIMS 2015, A]

Page 3 :
20., , Assertion: Two waves moving in a uniform string having, , 27., , uniform tension cannot have different velocities., , Two similar open organ pipe of length S0 cm and 50.5., , produce 3 beats per second when sounded together, T, , all waves in same string. Moreover speedof wave in a string, , (a), , 303 m/s, , (b), , 330 m/s, , depends on its elastie and inertial properties only., AIMS 2015, C], , (c), , 151.5m/s, , (d), , 603 m/s, , If both Assertion and Reason, , (a), , are correct, , and Reason, , 28., , A whistle S of frequency frevolves in a circle of radius Ra, , a constant speed v. What is the ratio of largest and smallest, , is the correct explanation of Assertion., , frequeney detected by a detector D at rest at a distance 28, , b), , If both Assertion and Reason are correct, but Reason, is not the correct explanation ofAssertion., , from the centre of circle as shown in figure ?., , (c), (d), , IfAssertion is correct but Reason is incorrect., Ifboth the Assertion and Reason are incorrect., , [AIIMS 2016, C, , (take c as speed of sound), , A train is moving on a straighttrack with speed 20 ms.It, is blowing its whistle at the frequency of 1000 Hz. The, , 21., , The, , AIIMS 2016, A, , velocity of sound in air is, , Reason: Elastic and inertial properties ofstring are same for, , cm, , D, , 1RS, , percentage change in the frequency heard by a person, , standing near the track as the train passes him is (speed of, , sound, , a), 22., , 23., , JEE Main 2015], , 320 ms) close to:, , 18% (b) 24%, , () 6%, , (d), , 2R, , 12%, , Two tuning forks with natural frequencies 340 Hz each move, relative to a stationary observer. One fork moves away from, the observer, while the other moves towards the observer, at the same speed. The observer hears beats of frequency 3, Hz. Find the speed of the tuning forks. [BITSAT 2015, S], (a) 1.5 m/s, b) 2 m/s, (c) Im/s (d) 2.5m/s, The frequency of a sonometer wire is 100 Hz. When the, , 2, 29., , weights producing the tensions are completely immersed in, water, the frequency becomes 80 Hz and on immersing the, , 24., , weights in a certain liquid, the frequency becomes 60 Hz., The specific gravity ofthe liquid is [BITSAT 2015, S, BN], (a) 1.42, (b) 1.77, (c) 1.82, (d) 1.21, An air column, closed at one end and open at the other,, , Assertion., , (d) If both the Assertion and Reason are incorrect., 30., , the frequency of sound that the observer hears in the echo, Take velocity of sound in air = 330 msl), , (a), 31., , suspended from point O such that BO is equal to 'x'. Further, it is observed that the, frequency of Ist harmonic in AB is, , LLC, , 2/2s, , (b) 2s, , (c), , 2v2s (d) 2s, , Apipe open at both ends has a fundamental frequency, air. The pipe is dipped vertically in water so that half of it is, , fin, , in water. The fundamental frequency of the air column is, , equal to 2nd harmonic frequency in CD. 'x' is, , ALIL, , JEE Main 2016, S], , supports is: (takeg=10 ms), , (a), 26., , A uniform string of length 20 m is, suspended from a rigid, A short wave pulse is introduced at its lowest end., , Support., lt starts moving up the string. The time taken to reach the, , NEET 2016, A], , 765 Hz (b) 800 Hz (c) 838 Hz (b) 885 Hz, A massless rod of, length L is suspended by two identical, strings AB and CD of equal length. A bloclk of mass m is, , [AIIMS 2016, C, , (c) IfAssertion is correct but Reason is incorrect., , 100cm, , reflected from the cliff is, , Assertion : The base of Laplace correction was that, exchange of heat between the region of compression and, rarefaction in air is negligible., Reason: Air is bad conductor ofheat and velocity of sound, If both Assertion and Reason are correct and Reason, is the correct explanation of Assertion., (b) If both Assertion and Reason are correct, but Reason, is not the correct explanation, of, , A Siren emitting a sound of frequency 800 Hz moves away, , from an observer towards a cliffat a speed of 15ms'. Then,, , (C+v), cW2, , (a), , column is 50 cm. The next larger length of the column, resonating with the same tuning fork is, NEET 2016, C], cm (b), () 150 cm d) 200cm, , (a) 66.7, , (d), , in air is quite large., , resonates with a tuning fork when the smallest length ofthe, , 25., , b)V2C, , (a), , JEE Main 2016, A, , now, , (a), , JAIIMS 2016, S]1, 32., , 2f, , 3f, , (b), , f, , (d), , A string oflength (is fixed at both ends. It is vibrating in it5, , 3Td overtone with maximum amplitude'a'. The amplitude ata, , BITSAT 2016, A], , distance /3 from one end is, , D, , B, , (a), , m, (a), , 5, , (b) 4L, , 33., , (), , 4, , (d) L, , a, , (b) 0, , (c), , 3a, , (d), , The two nearest harmonics ofa tube closed at one end an, open at other end are 220 Hz and 260 Hz. What is the, , fundamental, , frequency, , (a), , (b), , 20 Hz, , of the, , 30 Hz, , system?, , (c), , 40 Hz, , NEET 2017,A, (d), , 10 Hz

Page 4 :
34, , Two cars mov ing 1n opposite directions, approach each other, with speed ot 2 ms and 16.S m s respectively. The driver, of, , he first, , blows, , successi ve resonances arc produced at 20 cm and 73 cm of, , column length. Ifthe frequcncy of the tuning fork is 320 Hz,, , horn, , having a frequeney 400 Hz. The, frequency heard by the driver of the second car is [velocity, car, , a, , of sound 340 m s:, , 35., , INEET 2017.A|, (d) 350z, , (a) 6 l Hz (b) 411 Hz () 448H, (a), A train moving at a speed ot 220 ms towards, object. emits a sound of trequeney, , a, , the velocity ofsound in air at 27°C is, (a), 40., , stationary, , sound reaching the object gets retlected back to the train as, 41., , [AIIMS 2017, A], , 36., , 8cm, , the, , (c), , length of the open organ, NEET 2018, A|, 16cm, , (d) 12.5 cm, , Vibrations are produced in a vertical tube of length 150cm, , (a), , water is filled slowly in the tube. If the speed of sound in air, , is 340 m/s then the minimum height of water required for, , (a), , If both Assertion and Reason are correct and Reason, is the correct explanation of Assertion., , (b), , If both Assertion and Reason are correct. but Reason, is not the correct, , explanation of Assertion., , (c), , If Assertion is correct but Reason is incorrect., , (d), , Ifboth the Assertion and Reason are incorrect., , A, , (a) 90cm, 42., , of beats heard when the string and the tuning fork made to, , vibrate simultaneously is :, (a), , BITSAT 2017, A], , 4, , (b) 6, (c) 8, (d) 12, fork, is, used to produce resonance in a glass tube., Atuning, The length of the air column in this tube can be adjusted by, a variable piston. At room temperature of 27°C two, , (d) 25am, 50cm, frequency having amplitudes 10 mm,, , 75cm, , (c), , Three waves of equal, 4 mm and 7 mm arrive at a given point with successive phase, , AIIMS 2018, C], , is given by:, , 5, (d) 4, (b), A granite rod of 60 cm length is clamped at its middle point, and is set into longitudinal vibrations. The density of granite, is 2.7 x 10 kg/m* andits Young's modulus is 9.27 101 Pa., (a), , 43., , 6, , 7, , (c), , What will be the fundamental frequency ofthe longitudinal, vibrations?, JEE Main 2018, S], (a), , 44., , of the bridges. The value of M is, [BITSAT 2017, A]., (a) 25 kg (b) 5kg, (c) 12.5 kg, (d) 1/25 kg, , decreased by 2%, keeping the tension constant, the number, , (b), , difference of.The amplitude ofthe resulting wave in mm, , same tuning fork forming three antinodes for the samepositions, , A tuning fork of frequency 392 Hz, resonates with 50 cm, length of a string under tension (T). Iflength ofthe string is, , AIIMS 2018, C, , resonance is, , sonameter wire resonates with a given tuning fork forming, , standing waves with five antinodes between the two bridges, when a mass of 9 kg is suspended from the wire. When this, mass is replaced by a mass M, the wire resonates with the, , 39., , 350 m/s, , closed at one end by a tuning fork offrequency 340Hz. Now, , [AIIMS 2017, C], , 38., , INEET 2018, A, , 300 m/s (d), , (c), , ofthe, , 37., , pipe is 20 cm,, , (a) 13.2 cm (b), , echo. The frequency of the eclho as deteceted by the driver, , 3500 Hz, (b) 4000 Hz, 500 Hz, (d) 3000 Hz, Assertion : The fundemental frequency of an open organ, pipe increases as the temperature is increased., Reason: As the temperature increses, the velocity of sound, increases nmore rapidly than length, pipe., , 339 m/s (c), , The fundamental frequency in an open organ pipe is equal, to the third harmonic of a closcd organ pipe. Ifthe length of, the closed organ, pipe is, , 1000 Hz. Some of the, , ofthe train is (speed of sound in air is 330 ms, , 330 m/s (b), , 5kHz, , b), , 2.5 kHz, , (c), , 10kHz, , (d), , 7.5 kHz, , The wavelength oftwo waves are 50 and 51 cm respectively., Ifthe temperature of theroom is 20°C then what will be the, number of beats produced per second by these waves, when, , 45., , the speed ofsound at 0°C is 332 m/s? [BITSAT 2018, AJ, (a) 24, (b) 14, (d) none of these, (c) 10, 10 forks are arranged in increasing order of, frequency in, two, nearest, forks, tuning, produce 4, such a wayThe, that any, of, the, is, twice, lowest., highest frequency, beats/sec., , Possible highest and the lowest frequencies (in Hz) are, [BITSAT 2018, C], (a) 80 and 40, (b) 100 and 50, (c) 44 and 22, (d) 72 and 36