A closed and open organ pipe are tuned to the same frequency. What is the ratio of their lengths?

A proton and an alpha - particle are accelerated through the same pontential difference. What is the ratio of their de-Broglie wavelengths.

In an open organ pipe where 1st antinode occurs ?

Two wires of same material are subjected to the same tensions. What is the ratio of extensions produced if the length of the first wire is double that of the other while its radius is half that of the other

An open organ pipe can produce a fundamental note of frequency x. What will be the overtones produced in the pipes ?