A tuning fork vibrating with a sonometer having $20 cm$ wire produces $5$ beats per second. The beat frequency does not change if the length of the wire is changed to $21 cm.$ the frequency of the tuning fork (in Hertz) must be

The length of a sonometer wire tuned to a frequency of $250 Hz$ is $0.60$ metre. The frequency of tuning fork with which the vibrating wire will be in tune when the length is made $0.40$ metre is .... $Hz$

A sonometer wire is vibrating in resonance with a tuning fork. Keeping the tension applied same, the length of the wire is doubled. Under what conditions would the tuning fork still be is resonance with the wire ?

A wire of density $8 \times 10^3\,kg / m ^3$ is stretched between two clamps $0.5\,m$ apart. The extension developed in the wire is $3.2 \times 10^{-4}\,m$. If $Y =8 \times 10^{10}\,N / m ^2$, the fundamental frequency of vibration in the wire will be $......\,Hz$.

Unlike a laboratory sonometer, a stringed instrument is seldom plucked in the middle. Supposing a sitar string is plucked at about $\frac{1}{4}$th of its length from the end. The most prominent harmonic would be

The string of a violin has a frequency of $440 \,cps$. If the violin string is shortened by one fifth, its frequency will be changed to ........... $cps$