Question:
A U-tube having unequal arm-lengths has water in it. A tuning fork of frequency $440 \mathrm{~Hz}$ can set up the air in the shorter arm in its fundamental mode of vibration and the same tuning fork can set up the air in the longer arm in its first overtone vibration. Find the length of the air columns. Neglect any end effect and assume that the speed of sound in air $=330 \mathrm{~m} \mathrm{} \mathrm{s}^{-1}$.
Solution:
