Questions;
175:
Resonance
180:
Resonance
Question
175: Three pure tones of frequencies 4 Hz, 2 Hz and 1 Hz are
played one at a time near a taut string of length 1 ft that is tied
at both ends. It is observed that only the 4 Hz and the 2 Hz
tones make the string vibrate in allowed modes. From this
information, we could deduce
a)
the LNRF of the string
b)
the wave velocity for the string
c)
all the allowed wavelengths
d)
a and b
e)
b and c
f)
a, b and c
g)
none of the above
Fundamentals of
Sound reference: Chap. 4.
Question 180: Three pure tones of frequencies 9 Hz, 7 Hz and 4 Hz are played one at a time near a taut string of length 1 ft that is tied at both ends. It is observed that only the 9 Hz tone makes the string vibrate in one of its allowed modes. From this information, we could deduce
i) that the LNRF of the
string is 9 Hz
ii) that 9 Hz is either the LNRF or one of the other natural resonant
frequencies of the string
iii) the wave velocity for the string
iv) all the allowed wavelengths
a)
i only
b)
ii only
c)
iii only
d)
iv only
e)
ii and iv
f)
i, ii, iii, and iv
g)
none of the above
Fundamentals of Sound reference: Chap. 4.