IB PHYSICS HL MULTIPLE CHOICE REVIEW WAVES & VIBRATIONS

Transcription

1 IB PHYSICS HL MULTIPLE CHOICE REVIEW WAVES & VIBRATIONS. A sound emiing source moves along a sraigh line wih speed v relaive o an observer a res. Observer v The speed of sound relaive o he medium is c. The observer measures he speed of sound emied by he source as A. c. B. c + v. C. c v. D. v c. 2. The diagram below shows ocean waves inciden on a sone barrier proecing boas anchored behind i. Waves Boas Barrier The boas could sill be a risk of damage by waves mainly as a resul of A. refracion. B. sanding waves. C. diffracion. D. reflecion. 3. Two paricles X and Y are siuaed a disance apar on a saionary wave of wavelengh λ. The variaion 2 wih ime of he displacemen d x of X is shown below. d X Which one of he following correcly shows he variaion wih ime of he displacemen d Y of paricle Y? A. d Y B. d Y C. d Y D. d Y

2 4. The speed of a wave is defined as A. he speed a which he paricles of he wave vibrae. B. he speed of he medium hrough which he wave passes. C. he speed of ransfer of he energy of he wave. D. he speed a which he vibraions of he wave are produced. 5. Which diagram bes shows diffracion of plane wavefrons a a single sli? A. B. C. D. 6. A source of sound moves direcly owards a saionary observer. The frequency of he sound deeced by he observer is differen from he source frequency because A. he loudness of he sound increases as he source moves owards he observer. B. he apparen wavelengh of he sound is longer. C. he speed of sound relaive o he observer is increased. D. he apparen wavelengh of he sound is shorer. 2

3 7. A pipe, open a boh ends, has a lengh L. The speed of sound in he air in he pipe is v. The frequency of vibraion of he fundamenal (firs harmonic) sanding wave ha can be se up in he pipe is A. v 2 L. B. L v 2. C. L 4 v L. D. 4 v. 8. Two lamps producing ligh of he same colour are placed close o one anoher. A wo source inerference paern is no observed because A. he lamps do no emi ligh of a single frequency. B. he phase difference beween he ligh from he lamps is coninually changing. C. he inensiy of he ligh emied by he lamps is no he same. D. he wo lamps are no exac poin sources. 9. Sanding waves in an open pipe come abou as a resul of A. reflecion and superposiion. B. reflecion and diffracion. C. superposiion and diffracion. D. reflecion and refracion.. A source of sound emis waves of wavelengh λ, period T and speed v when a res. The source moves away from a saionary observer a speed V, relaive o he observer. The wavelengh of he sound waves, as measured by he observer is A. λ + vt. B. λ vt. C. λ +VT. D. λ VT. 3

4 . Which of he following diagrams bes illusraes he diffracion of waves by an obsacle? A. B. C. D. 2. A source S produces sound waves of frequency f and is moving along a sraigh line as shown below. I S IV II III Which observer I, II, III or IV could hear a sound of frequency f when he source is in he posiion shown? A. I B. II C. III D. IV 3. In order ha he inerference beween he waves emied by wo ligh sources can be observed, i is essenial ha he sources mus emi waves ha A. have he same ampliude. B. are in phase. C. have he same colour. D. have a consan phase difference beween hem. 4

5 4. Graph P shows how he displacemen a one poin in a wave varies wih ime. Graph Q shows how he displacemen in he same wave varies wih disance along he wave a one paricular ime. Graph P displacemen 2 ime Graph Q displacemen x x x 2 3 disance Which one of he following expressions gives he speed of he wave? A. x B. x 2 2 C. x 2 2 x D. x 3 2 x 5. A sring is sreched beween wo fixed poins. The sring is plucked a is cenre and is seen o vibrae wih frequency f as shown below. Which one of he following expressions gives he frequencies of oher possible modes of vibraion ha have an aninode a he cenre? The number n in each expression is an ineger. A. nf B. (2n )f C. (n )f D. (n + )f 5

6 6. Which one of he following diagrams bes represens wavefrons produced by a source of sound of consan frequency as i moves a consan speed owards a saionary observer a O? A. B. O O C. D. O O 7. The waves from wo ligh sources mee a a poin. Which condiion is essenial for inerference o be observed? A. Consan phase difference beween he waves B. Equal ampliude of he waves C. Equal frequency of he waves D. Equal inensiies of he waves 8. Ligh from a double sli arrangemen produces brigh and dark fringes on a screen in he region near poin P, as indicaed below. coheren ligh P double sli no o scale screen The ligh from he wo slis has equal ampliudes on reaching poin P. Which one of he following gives he change, if any, in he appearance of he brigh and he dark fringes when he ampliude of he ligh wave from one sli is reduced? Brigh fringes Dark fringes A. Remains he same Remains he same B. Becomes less brigh Remains he same C. Becomes less brigh Becomes more brigh D. Remains he same Becomes more brigh 6

7 9. The speed of sound in sill air is c. A source of sound moves away from an observer a speed v. Wha will be he speed of sound as measured by he observer? A. c B. c + v C. c v D. v c 2. For a sanding wave, all he paricles beween wo successive nodes have he same A. ampliude only. B. frequency only. C. ampliude and frequency. D. frequency and energy. 2. The diagram below shows wo pulses on a sring ravelling oward each oher. Which of he following diagrams bes shows he shape of he sring afer he pulses have passed hrough each oher? A. B. C. D. 7

8 22. Two idenical sources in a ripple ank generae waves of wavelengh λ. The inerfering waves produce he wave paern shown below. II III I IV Along which of he labelled lines is he pah difference beween he waves from he sources equal o.5 λ? A. I B. II C. III D. IV 23. Which one of he following is correc for ransfer of energy along a sanding wave and for ampliude of vibraion of he sanding wave? Transfer of energy along a sanding wave Ampliude of vibraion of he sanding wave A. None Consan ampliude B. None Variable ampliude C. Energy is ransferred Consan ampliude D. Energy is ransferred Variable ampliude 24. Two pipes P and Q are of he same lengh. Pipe P is closed a one end and pipe Q is open a boh ends. The fundamenal frequency (firs harmonic) of he closed pipe P is 22 Hz. The bes esimae for he fundamenal frequency of he open pipe Q is A. 88 Hz. B. 44 Hz. C. Hz. D. 55 Hz. 8

9 25. In order ha he ligh from wo sources produces an observable inerference paern, i is necessary ha A. he sources mus be poin sources. B. he ligh emied by he sources mus be monochromaic. C. he ligh from each source mus be of he same inensiy. D. he ligh from he sources mus be coheren. 26. Monochromaic ligh crosses he boundary beween wo media. Which of he following quaniies is always he same for he ligh in boh media? A. Ampliude B. Frequency C. Speed D. Wavelengh 27. A poin source is moving a a consan speed in a sraigh-line owards he righ and emis sound waves of consan frequency. The speed of he source is less han he speed of sound. Which of he diagrams correcly shows he wavefrons emied by he source? A. B. C. D. 9

10 28. The diagram below shows he arrangemen for a Young s double sli experimen. single sli double sli S monochromaic ligh source S S 2 The funcion of he single sli is A. o direc he ligh owards S and S 2. B. o ensure equal inensiies of ligh a S and S 2. C. o produce coheren ligh a S and S 2. D. o reduce he inensiy of ligh a S and S Which one of he following correcly describes he change, if any, in he speed, wavelengh and frequency of a ligh wave as i passes from air ino glass? Speed Wavelengh Frequency A. decreases decreases unchanged B. decreases unchanged decreases C. unchanged increases decreases D. increases increases unchanged

11 3. A ube is filled wih waer and a vibraing uning fork is held above is open end. x uning fork y waer ap The ap a he base of he ube is opened. As he waer runs ou, he sound is loudes when he waer level is a disance x below he op of he ube. A second loud sound is heard when he waer level is a disance y below he op. Which one of he following is a correc expression for he wavelengh of he sound produced by he uning fork? A. = y B. = 2x C. = y x D. = 2(y x) 3. A source S, moving a consan speed, emis a sound of consan frequency. The source passes by a saionary observer O, as shown below. S O Which one of he following shows he variaion wih ime of he frequency f observed a O as he source S approaches and passes by he observer. A. f B. f C. f D. f

12 32. Waer waves of wavelengh 2. m are produced by wo sources S and S 2. The sources vibrae in phase. S S 2 m 3 m P Poin P is m from S and 3 m from S 2. S alone and S 2 alone each produce a wave of ampliude a a P. Which one of he following is he ampliude of he resulan wave a poin P when S and S 2 are boh emiing waves? A. 2a B. a C. a 2 D. Zero 33. A source of sound is placed near he open end of a cylindrical ube ha lies on a horizonal able. The ube has some powder sprinkled along is lengh. The powder collecs in piles along he lengh of he ube as shown below. source of sound d The disance beween wo consecuive piles of powder is d and he speed of sound in he ube is v. The frequency of he source is v A.. 2d v B.. d C. dv. D. 2dv. 34. A well-insulaed conainer is divided ino wo equal volumes by a wall. In one half here is an ideal gas and he oher is a vacuum as shown below. gas vacuum gas The wall is now removed. Which one of he following correcly gives he changes, if any, ha ake place in he inernal energy and enropy of he gas? Inernal energy Enropy A. says he same says he same B. says he same increases C. decreases says he same D. decreases increases 2

13 35. The disance S 2 N S N is equal o c A.. 2 f c B.. f f C.. 2c f D.. c 36. A saionary source emis sound of frequency f. An observer is moving owards he source a consan speed along he pah indicaed by he doed line. The observer passes very close o he source a ime T. observer saionary source Which one of he following graphs bes shows he variaion wih ime of he frequency f heard by he observer? A. f B. f f f T T C. f D. f f f T T 37. A police car, sounding is siren, is ravelling a consan speed owards a saionary observer. The sound emied by he siren is of consan frequency. The frequency of he sound as heard by he observer is higher han ha heard by he driver of he police car. The reason for his is ha A. he wavefrons received by he observer are closer ogeher han he wavefrons received by he driver. B. he speed of he wavefrons is greaer as measured by he observer han by he driver. C. he speed of he wavefrons is less as measured by he observer han by he driver. D. he wavefrons received by he observer are furher apar han he wavefrons received by he driver. 38. The ligh waves emied by wo coheren sources overlap and form an observable inerference paern. The word coheren in his siuaion means ha A. he sources are poin sources. B. here is a consan phase difference beween he ligh waves emied by he sources. C. he sources emi ligh of he same frequency. D. he sources emi ligh of he same ampliude. 3

14 39. A vibraing uning fork is held above he op of a ube ha is filled wih waer. The waer gradually runs ou of he ube unil a maximum loudness of sound is heard. Which of he following bes shows he sanding wave paern se up in he ube a his posiion? A. B. C. D. 4. Which of he following is a correc descripion of he Doppler effec? A. Change in frequency of ligh due o moion of he source of ligh. B. Change in frequency of ligh due o relaive moion beween he source of ligh and he observer. C. Change in observed frequency of ligh due o relaive moion beween he source of ligh and he observer. D. Change in observed frequency of ligh due o change in velociy of he source of ligh. 4. In a double-sli experimen using coheren ligh of wavelengh, he cenral brigh fringe is observed on a screen a poin O, as shown below. P coheren ligh wavelengh O double sli screen (no o scale) A poin P, he pah difference beween ligh arriving a P from he wo slis is 4. Which of he following correcly describes he observed fringe paern? naure of fringe a P number of dark fringes beween O and P A. brigh 3 B. brigh 4 C. dark 3 D. dark 4 4

15 42. A sring wih boh ends fixed is made o vibrae in he second harmonic mode as shown by he dashed lines in he diagram below. P Q The solid line shows a phoograph of he sring a a paricular insan of ime. Two poins on he sring have been marked P and Q. Which of he following correcly compares boh he period of vibraion of P and Q and he average speed of P and Q? Period Average speed A. same same B. same differen C. differen same D. differen differen 43. The diagram below represens he fundamenal (firs harmonic) sanding wave of sound inside a pipe. P Q pipe Which of he following correcly represens he displacemen of he air a P and Q? P Q A. B. C. D. 5

16 44. Which saemen is rue for sanding (saionary) waves? A. All poins in he wave vibrae in phase. B. There is no energy in a sanding wave. C. The wavelengh of he wave is he disance beween adjacen nodes. D. Neighbouring poins in he wave have differen ampliudes of vibraion. 45. A saionary source of sound emis waves of wavelengh λ, period T and speed V. The source now moves wih speed v in a sraigh line away from a saionary observer. Wha are he wavelengh and he speed of he wave as deeced by he observer? wavelengh speed A. λ V + v B. λ vt V C. λ V v D. λ + vt V 46. Which wo condiions are necessary for observable inerference beween wo ligh beams? A. mee a a poin consan phase difference B. consan phase difference similar ampliude C. same frequency similar ampliude D. similar ampliude mee a a poin 47. A sanding wave is esablished on a sring beween wo fixed poins. T A B D U C A he insan shown, poin T is moving downwards. Which arrow gives he direcion of movemen of poin U a his insan? A. A B. B C. C D. D 6

17 48. The diagrams below show wo sanding wave paerns ha are se up in a sreched sring fixed a boh ends. The frequency of paern is f and ha of paern 2 is f 2. paern frequency f paern 2 frequency f 2 The raio f f 2 is A. 2. B.. C. 3. D Sound of a consan frequency f is being emied by a sound source. An observer O ravels in he direcion shown a a speed of. v where v is he speed of sound. observer O sound source Which of he following gives he relaionship beween f and he frequency f of observed sound? A. f =.f B. f < f <.f C. f =.9f D. f > f >.9f ( 5. The wo graphs show he variaion wih ime of he individual displacemens of wo waves as hey pass hrough he same poin. The displacemen of he resulan wave a he poin a ime T is equal o A. x + x 2. B. x x 2. C. A + A 2. D. A A 2. 7

18 5. A ube is filled wih waer and a vibraing uning fork is held above is open end. The ap a he base of he ube is opened. As he waer runs ou, he sound is loudes when he waer level is a disance x below he op of he ube. A second loud sound is heard when he waer level is a disance y below he op. Which of he following is a correc expression for he wavelengh of he sound produced by he uning fork? A. = y B. = 2x C. = y x D. = 2(y x) 52. A source S, moving a consan speed, emis a sound of consan frequency. The source passes by a saionary observer O, as shown below. Which of he following shows he variaion wih ime of he frequency f observed a O as he source S approaches and passes by he observer? 8

19 . A 2. C 3. A 4. C 5. A 6. D 7. A 8. B 9. A. C. B 2. B 3. D 4. C 5. B 6. A 7. A 8. C MARK SCHEME! 9. A 2. B 2. B 22. C 23. B 24. B 25. D 26. B 9

20 27. B 28. C 29. A 3. D 3. C 32. A 33. A 34. B 35. B 36. A 37. A 38. B 39. C 4. C 4. B 42. B 43. A 44. D 45. D 46. A 47. D 48. A 49. B 5. B 5. D 52. C 2