1. The problem statement, all variables and given/known data Q. A hollow metallic tube closed at one end produces resonance with a tuning fork of frequency n at temperature T. The temperature of the tube is increased by dT. If the coefficient of thermal expansion of the tube metal is alpha, the beat frequency will be - (there are 4 option in the attached image) 2. Relevant equations Frequency for a tube closed at one end - n=v/(4l),3v/(4l).... 3. The attempt at a solution I have no idea ho to get the solution in terms of temperature and coefficient of thermal expansion.