Question 1

For a diffraction horn loudspeaker, the sound emerges through a rectangular opening. The width of a diffraction horn is 0.14 m. If the speed of sound in air is 343 m/s, at what frequency is the diffraction angle $\theta$ equal to 35°?

Accepted Answer

A) 3300 Hz 
B) 4300 Hz 
C) 6300 Hz 
D) 7700 Hz 
E) 9200 Hz

Question 2

A guitar string produces 4 beats/s when sounded with a 250 Hz tuning fork and 9 beats per second when sounded with a 255 Hz tuning fork. What is the vibrational frequency of the string?

Accepted Answer

A) 240 Hz 
B) 246 Hz 
C) 254 Hz 
D) 259 Hz 
E) 263 Hz

Question 3

Which one of the following statements is true concerning the points on a string that sustain a standing wave pattern?

Accepted Answer

A) All points vibrate with the same energy. 
B) All points undergo the same displacements. 
C) All points vibrate with different frequencies. 
D) All points vibrate with different amplitudes. 
E) All points undergo motion that is purely longitudinal.

Question 4

A speaker is designed for wide dispersion for a high frequency sound. What should the diameter of the circular opening be for a speaker where the desired diffraction angle is 11° and a 9100 Hz sound is generated? The speed of sound is 343 m/s.

Accepted Answer

A) 0.039 m 
B) 0.077 m 
C) 0.24 m 
D) 0.13 m 
E) 0.048 m

Question 5

A string with a length of 3.0 m has two adjacent resonances at frequencies 112 Hz and 140 Hz.
-Determine the speed of the waves on the string vibrating at 140 Hz..

Accepted Answer

A) 28 m/s 
B) 42 m/s 
C) 56 m/s 
D) 140 m/s 
E) 168 m/s

Question 6

A cylindrical tube sustains standing waves at the following frequencies: 600 Hz, 800 Hz, and 1000 Hz. The tube does not sustain standing waves at 500 Hz, at 900 Hz, at any frequencies between 600 and 800 Hz, or at any frequencies between 800 and 1000 Hz. Determine the fundamental frequency of the tube and whether the tube is open at both ends or has only one end open.

Accepted Answer

A) 50 Hz, both ends 
B) 100 Hz, one end 
C) 100 Hz, both ends 
D) 200 Hz, one end 
E) 200 Hz, both ends

Exam 17: The Principle of Linear Superposition and Interference Phenomena

For a diffraction horn loudspeaker, the sound emerges through a rectangular opening. The width of a diffraction horn is 0.14 m. If the speed of sound in air is 343 m/s, at what frequency is the diffraction angle θ\thetaθ equal to 35°?

A guitar string produces 4 beats/s when sounded with a 250 Hz tuning fork and 9 beats per second when sounded with a 255 Hz tuning fork. What is the vibrational frequency of the string?

Which one of the following statements is true concerning the points on a string that sustain a standing wave pattern?

A speaker is designed for wide dispersion for a high frequency sound. What should the diameter of the circular opening be for a speaker where the desired diffraction angle is 11° and a 9100 Hz sound is generated? The speed of sound is 343 m/s.

A string with a length of 3.0 m has two adjacent resonances at frequencies 112 Hz and 140 Hz. -Determine the speed of the waves on the string vibrating at 140 Hz..

For a diffraction horn loudspeaker, the sound emerges through a rectangular opening. The width of a diffraction horn is 0.14 m. If the speed of sound in air is 343 m/s, at what frequency is the diffraction angle $\theta$ equal to 35°?