Principle of superposition, reflection of waves, standing waves in strings and organ pipes, fundamental mode and harmonics, beats - Question Bank

1. In an organ pipe open at both ends, if the fundamental frequency is 100 Hz, what is the frequency of the second overtone?
A) 200 Hz
B) 300 Hz
C) 400 Hz
D) 500 Hz
2. A standing wave is formed on a string of length L. If the string vibrates in 3 segments (3 antinodes), what is the wavelength?
A) L
B) 2L
C) 2L/3
D) 3L/2
3. What is the condition for resonance in an organ pipe?
A) The length of the pipe is an integer multiple of half wavelengths.
B) The length of the pipe is an odd multiple of quarter wavelengths.
C) The frequency of the source matches one of the natural frequencies of the pipe.
D) The length of the pipe is equal to the wavelength.
4. When two waves of amplitudes A1 and A2 interfere, the resultant amplitude R depends on their phase difference φ. The formula for R^2 is:
A) A1^2 + A2^2 + 2A1A2 cos φ
B) A1^2 + A2^2 - 2A1A2 cos φ
C) A1^2 + A2^2 + 2A1A2 sin φ
D) A1^2 + A2^2 - 2A1A2 sin φ
5. A tuning fork of frequency 440 Hz is sounded with another tuning fork. 4 beats are heard per second. If the frequency of the unknown tuning fork is slightly increased, and the beat frequency becomes 5 per second, what was the original frequency of the unknown tuning fork?
A) 436 Hz
B) 444 Hz
C) 430 Hz
D) 450 Hz
6. A tuning fork of frequency 440 Hz is sounded with another tuning fork. 4 beats are heard per second. The frequency of the second tuning fork could be:
A) 436 Hz
B) 444 Hz
C) 430 Hz
D) 450 Hz
7. Beats are perceived as periodic variations in:
A) Frequency
B) Wavelength
C) Amplitude (loudness)
D) Speed
8. To produce beats, the frequencies of the two waves must be:
A) Identical
B) Very different
C) Slightly different
D) Zero
9. If two sound waves have frequencies f1 and f2 (f1 > f2), the beat frequency is:
A) f1 + f2
B) f1 - f2
C) (f1 + f2) / 2
D) f1 * f2
10. The number of beats heard per second is equal to the:
A) Sum of the frequencies of the two waves.
B) Difference between the frequencies of the two waves.
C) Average of the frequencies of the two waves.
D) Product of the frequencies of the two waves.
11. Beats are produced when two sound waves of slightly different frequencies interfere. This phenomenon is known as:
A) Interference
B) Diffraction
C) Beating
D) Resonance
12. In an organ pipe closed at one end, the first overtone corresponds to the:
A) Second harmonic
B) Third harmonic
C) Fifth harmonic
D) Fourth harmonic
13. In an organ pipe open at both ends, the first overtone corresponds to the:
A) Second harmonic
B) Third harmonic
C) Fourth harmonic
D) Fundamental mode
14. In a string fixed at both ends, the first overtone corresponds to the:
A) Fundamental mode
B) Second harmonic
C) Third harmonic
D) Second overtone
15. What are overtones in the context of standing waves?
A) Frequencies that are integer multiples of the fundamental frequency.
B) Frequencies that are odd integer multiples of the fundamental frequency.
C) Frequencies higher than the fundamental frequency.
D) Frequencies that are even integer multiples of the fundamental frequency.
16. If the fundamental frequency of an organ pipe closed at one end is f0, the frequency of the third harmonic (which is the second overtone) is:
A) 2f0
B) 3f0
C) 4f0
D) 5f0
17. The frequencies of vibration for an organ pipe closed at one end are:
A) All integer multiples of the fundamental frequency
B) Odd harmonics only
C) Even harmonics only
D) Only the fundamental frequency
18. For an organ pipe closed at one end, the condition for standing waves is:
A) L = nλ/2
B) L = (2n-1)λ/4
C) L = nλ
D) L = (2n-1)λ/2
19. In an organ pipe closed at one end, what must be present at the open end and the closed end, respectively?
A) Node, Antinode
B) Antinode, Node
C) Node, Node
D) Antinode, Antinode
20. The frequencies of vibration for an organ pipe open at both ends are:
A) Harmonics only
B) Odd harmonics only
C) Even harmonics only
D) All integer multiples of the fundamental frequency
21. For an organ pipe open at both ends, the condition for standing waves is:
A) L = nλ/2
B) L = nλ
C) L = λ/2
D) L = (2n-1)λ/4
22. In an organ pipe open at both ends, what must be present at the ends?
A) Nodes
B) Antinodes
C) One node and one antinode
D) No specific condition
23. Harmonics are integer multiples of the fundamental frequency. This applies to:
A) Organ pipes closed at one end
B) Open strings
C) Organ pipes open at both ends
D) All musical instruments
24. If the fundamental frequency of a string is f0, the frequency of the third harmonic is:
A) f0
B) 2f0
C) 3f0
D) f0/3
25. If the fundamental frequency of a string is f0, the frequency of the second harmonic is:
A) f0
B) 2f0
C) 3f0
D) f0/2
26. For a string of length L fixed at both ends, the frequency of the nth harmonic is given by:
A) nv / 2L
B) nv / L
C) v / 2L
D) nv / 4L
27. The frequency of the fundamental mode is also known as the:
A) Second harmonic
B) First overtone
C) First harmonic
D) Third harmonic
28. In the fundamental mode of vibration of a string fixed at both ends, how many antinodes are present?
A) Zero
B) One
C) Two
D) Three
29. The lowest frequency of vibration of a string fixed at both ends is called the:
A) Harmonic
B) Fundamental mode
C) Overtones
D) Resonance frequency
30. In a string fixed at both ends, the ends must be:
A) Antinodes
B) Nodes
C) Crests
D) Troughs
31. For a string of length L fixed at both ends, what is the condition for the formation of standing waves?
A) L = nλ/2
B) L = nλ
C) L = λ/2
D) L = 2λ
32. What is the distance between a node and an adjacent antinode in a standing wave?
A) λ
B) λ/2
C) 2λ
D) λ/4
33. What is the distance between two consecutive antinodes in a standing wave?
A) λ
B) λ/2
C) 2λ
D) λ/4
34. What is the distance between two consecutive nodes in a standing wave?
A) λ
B) λ/2
C) 2λ
D) λ/4
35. In a standing wave, points of maximum displacement are called:
A) Nodes
B) Antinodes
C) Crests
D) Troughs
36. In a standing wave, points of minimum displacement are called:
A) Antinodes
B) Nodes
C) Crests
D) Troughs
37. What are standing waves?
A) Waves that travel through a medium, transferring energy.
B) Waves formed by the superposition of two identical waves traveling in opposite directions.
C) Waves that exhibit interference patterns.
D) Waves generated by a vibrating source.
38. A wave traveling in a denser medium strikes a rarer medium at its boundary. What type of reflection occurs?
A) Reflection with phase change of π
B) Reflection without phase change
C) Total internal reflection
D) No reflection occurs
39. A wave traveling in a rarer medium strikes a denser medium at its boundary. What type of reflection occurs?
A) Reflection without phase change
B) Reflection with phase change of π
C) No reflection occurs
D) Partial reflection and partial transmission
40. When a wave is reflected from a free boundary, what happens to its phase?
A) It remains unchanged.
B) It changes by π radians (180 degrees).
C) It changes by π/2 radians (90 degrees).
D) It halves.
41. When a wave is reflected from a rigid boundary, what happens to its phase?
A) It remains unchanged.
B) It changes by π radians (180 degrees).
C) It changes by π/2 radians (90 degrees).
D) It doubles.
42. According to the law of reflection, the angle of incidence is equal to the:
A) Angle of refraction
B) Angle of diffraction
C) Angle of reflection
D) Angle of transmission
43. When a wave encounters a boundary, it bounces back into the same medium. This phenomenon is called:
A) Refraction
B) Diffraction
C) Interference
D) Reflection
44. If two waves with amplitudes A1 and A2 interfere destructively, what is the minimum possible amplitude of the resultant wave?
A) A1 + A2
B) A1 - A2
C) √(A1^2 + A2^2)
D) √(A1^2 - A2^2)
45. If two waves with amplitudes A1 and A2 interfere constructively, what is the maximum possible amplitude of the resultant wave?
A) A1 + A2
B) A1 - A2
C) √(A1^2 + A2^2)
D) √(A1^2 - A2^2)
46. Destructive interference occurs when two waves meet with displacements in opposite directions. What is the condition for destructive interference?
A) Phase difference is an even multiple of π.
B) Phase difference is an odd multiple of π.
C) Path difference is an even multiple of λ/2.
D) Path difference is an integer multiple of λ.
47. Constructive interference occurs when two waves meet with displacements in the same direction. What is the condition for constructive interference?
A) Phase difference is an odd multiple of π.
B) Phase difference is an even multiple of π.
C) Path difference is an odd multiple of λ/2.
D) Path difference is zero.
48. When two waves meet at a point, the resultant displacement is equal to the algebraic sum of the displacements due to each wave individually. This statement describes which principle?
A) Huygens' Principle
B) Principle of Superposition
C) Doppler Effect
D) Principle of Reflection
49. What is the principle of superposition for waves?
A) The resultant displacement is the sum of individual displacements due to each wave.
B) The resultant displacement is the product of individual displacements.
C) The resultant displacement is the difference between individual displacements.
D) The resultant displacement is the average of individual displacements.