In fundamental mode, the time required for the sound wave to reach up to closed end of a pipe filled with air is ' $t$ ' second. The frequency of vibration of air column is (Neglect end correction)

Two pipes of lengths $\mathrm{L}_1$ and $\mathrm{L}_2$, open at both ends are joined in series. If ' $f_1$ ' and ' $f_2$ ' are the fundamental frequencies of two pipes, then the fundamental frequency of series combination will be (neglect end correction)

A wire of length L , diameter ' d ' density of material ' e ' is under tension ' T ', having fundamental frequency of vibration $\mathrm{n}_{\mathrm{A}}$. Another wire of length 2 L , tension 2 T , density 2 e and diameter 3 d has fundamental frequency of vibration $\mathrm{n}_{\mathrm{B}}$. The ratio $\mathrm{n}_{\mathrm{B}}: \mathrm{n}_{\mathrm{A}}$ is

The frequency of a tuning fork is 256 Hz . It will not resonate with the tuning fork of frequency