A source of sound emits sound wave of frequency ' f ' and moves towards an observer with a velocity $\frac{\mathrm{V}}{3}$ where V is the velocity of sound. If the observer moves away from the source with a velocity $\frac{\mathrm{V}}{5}$ the apparent frequency heard by him will be

An air column is of length 17 cm . The ratio of frequencies of $5^{\text {th }}$ overtone if the air column is closed at one end to that open at both ends is (velocity of sound in air $=340 \mathrm{~ms}^{-1}$ )

In Sonometer experiment, the frequency of a tuning fork used is 288 Hz . Harmonics will 'NOT' be produced at the frequency