Waves Mock Test – Class 11 Physics

1. Two media are compared for sound propagation. Medium P has a stronger elastic restoring effect but similar inertia compared with medium Q. The sound speed in P is expected to be

2. A pipe closed at one end and open at the other vibrates in its fundamental mode. The length of the air column is

3. A periodic wave has frequency and wavelength . Another wave in the same medium has frequency . If the medium fixes the speed, the wavelength of the second wave is

4. An open pipe of physical length has end correction at each end. A closed pipe of physical length has the same end correction at its open end. Both contain air with sound speed . The ratio of their fundamental frequencies is closest to

5. The following statements describe sound characteristics.
I. Increasing frequency generally increases perceived pitch.
II. Increasing amplitude can increase loudness through greater intensity.
III. Quality depends only on wave speed in air and not on waveform.
The supported statements are

6. A tuning fork gives beats per second with a standard fork. When is filed slightly, the beat frequency becomes beats per second. The original frequency of was

7. Beats are most clearly heard when two sound waves reaching the ear have

8. If end correction is supplied for an open end of a pipe, the effective length of a pipe open at both ends is

9. The equation represents a sinusoidal wave travelling in

10. A source and observer move away from each other along the same straight line in still air. If the source frequency is , sound speed is , observer speed is , and source speed is , the observed frequency is closest to

11. A cork floating on water moves up and down as ripples pass across the surface. The ripples travel outward, but the cork does not travel outward with them. This observation mainly shows that

12. At an open end of a pipe supporting a standing sound wave, the usual boundary condition is

13. A gas at has sound speed . The same gas is heated so that the sound speed becomes . The final temperature is

14. A closed pipe has fundamental frequency . The next higher resonant frequency is

15. The allowed harmonics of an ideal pipe closed at one end and open at the other are

16. Match the wave examples with their basic type.

17. A resonance tube closed at one end gives first and third resonance lengths and for a tuning fork. The frequency of the tuning fork is . Neglecting change of end correction between resonances, the speed of sound is

18. A source and observer are moving in the same direction through still air. The source is behind the observer, and both have the same speed. The sound from the source travels forward toward the observer. The observed frequency is

19. A claim says, “The slope of a graph at a point tells the direction in which the wave will move next.” The better correction is that

20. A wave on a string is described by in SI units. The string has . If this wave speed is due to string tension, the tension is

21. A sound wave cannot travel through a perfect vacuum because

22. A stationary listener hears the echo of sound reflected from a stationary wall. A source of frequency moves toward the wall with speed . If the speed of sound in air is , the echo frequency heard by the stationary listener is closest to

23. A source and observer move toward each other. The source emits , the source speed is , and the observer speed is . If the observed frequency is , the speed of sound is closest to

24. Study the table and identify the mismatched quantity-unit pair.

25. Use the graph description below.

The two sounds mainly differ in

26. A graph of a sinusoidal wave is compared at and a later time . The entire graph has shifted to the right, while its shape and amplitude are unchanged. A suitable phase form is

27. A train moving toward a stationary observer emits , and the observer hears . If the speed of sound is , the train speed is closest to

28. A wave carrying energy falls normally on a small surface. If is the power crossing area , the intensity is

29. Study the table and choose the row that gives the suitable interpretation.

The row that is not suitable is

30. A phase changes by when position changes by one wavelength. This statement leads to

31. A source of frequency and an observer move toward each other. The observer speed is , the source speed is , and the speed of sound is . The wavelength of sound in front of the moving source and the observed frequency are respectively

32. A standing wave is given by . At a position where , the amplitude of oscillation is

33. A point source sends sound uniformly in all directions. As the sound spreads farther from the source, the same total power is distributed over a larger spherical surface. The intensity therefore

34. A wave is described by . How far does a fixed phase point of this wave move in ?

35. In the expression , the quantity is called

36. Study the table and choose the row with a mismatched unit.

37. Assertion: Sound cannot be heard across a perfect vacuum.
Reason: Sound is a mechanical wave that needs a material medium to carry pressure disturbances.

38. A supersonic aircraft produces a Mach cone of semi-angle . If the local speed of sound is , the aircraft speed is closest to

39. A sound has intensity and amplitude . Another sound of the same frequency in the same medium has amplitude . Its intensity is

40. For many mechanical waves under the same conditions, intensity is proportional to the square of amplitude. If the amplitude becomes , the intensity becomes

41. Assertion: A wave on a stretched string is usually represented with crests and troughs.
Reason: In a transverse wave, the displacement of string particles is perpendicular to the direction of propagation.

42. A wave of frequency travels from string P to string Q under the same tension. String P has , and string Q has . If the wavelength in P is , the tension and wavelength in Q are respectively

43. The quantity that tells how many complete oscillations occur in is

44. A student uses for a sound source moving toward a stationary observer. The same formula is then used for a moving observer approaching a stationary source. The error is that

45. A graph is drawn between wave speed and wavelength for waves of a fixed frequency . The graph should be

46. A string fixed at both ends is vibrating in a mode whose equation is consistent with , where is in . If the string length is , the harmonic number and wave speed are respectively

47. A wave has amplitude and intensity . To make the intensity one-fourth, the amplitude should become

48. A sinusoidal wave has . The path difference for a phase difference of is

49. A fixed string of length has linear mass density and is stretched by tension . Its second harmonic frequency is closest to

50. Two identical waves of the same amplitude and frequency travel along the same string in opposite directions. Their superposition can form