PHYS 536, Winter 2023

All work on this exam must be your own.   Open books and notes.  
There are 10 questions, multiple choice.
Using any text editor (Word, TextEdit, Notepad, etc), type in the letter of the best answer for each question in the answer sheet provided as the last page.  
Choose only one answer for each question.  


1. Standing waves are produced in 10m long stretched string. If the string vibrates in 5 segments and wave velocity is 20m/s, its frequency is
a) 2Hz
b) 4Hz
c) 5Hz
d) 10Hz


2. The frequency of a tuning fork is 256 Hz. It will NOT resonate with a fork of frequency
a) 256 Hz
b) 512 Hz
c) 738 Hz
d) 768 Hz


3. An organ pipe closed at one end has a fundamental frequency of 1500Hz. The maximum number of overtones (number of harmonics above the fundamental) generated by this pipe, which a normal person can hear is
a) 12
b) 9
c) 6
d) 4


4. A closed organ pipe and an open pipe of the same length produce four beats per second, when sounded together. If the length of the closed pipe is increased, then the number of beats will
a) Increase
b) Decrease
c) Remain the same
d) First decrease then remain the same


5. When the amplitude of a sound pressure wave is doubled, the sound pressure level (in
decibels) 

a) is doubled.
b) is halved.
c) decreases by 2 dB.
d) increases by 6 dB

6. The trigonometric Fourier series of an even function of time does not have 
 
a. a DC term
b. cosine terms
c. sine terms
d. odd harmonic terms


7. Within reasonable limits, which of the following should NOT affect the fundamental frequency of vibration of a string?

a) changing the amplitude of vibration.
b) changing the tension of the string.
c) changing the length of the string.
d) changing the density (mass per meter) of the string.


8. Two pure tones cause resonance in different positions along the basilar membrane in the cochlea. These tones have different

a) amplitude.
b) frequency.
c) timbre.


9. What is the sound pressure level (SPL) of a sound having a RMS pressure of 200 N/m2?

a) 150 dB
b) 140 dB
c) 170 dB
d) 160 dB


10. What is the resonant frequency of a Helmholtz resonator whose volume is 2.5 cubic m with neck radius of 8 cm and effective neck length of 0.135 m ? (use c=331 m/s)

a) 13 Hz
b) 11 Hz
c) 15 Hz
d) 14 Hz
 



ANSWER SHEET = NEXT PAGE

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PHYS 536 2023 EXAM - ANSWER SHEET:

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