A uniform wire of length $L$, diameter $D$ and density $\rho$ is stretched by a tension $T$ length $L$ and…

A uniform wire of length $L$, diameter $D$ and density $\rho$ is stretched by a tension $T$ length $L$ and the diameter $D$ is
  1. $f \propto \frac{L}{D}$
  2. $f \propto \frac{1}{L D}$
  3. $f \propto \frac{1}{L \sqrt{D}}$
  4. $f \propto \frac{1}{L D^2}$

Solution

Given, Frequency $=f$, Diameter $=D$, Length $=L$, Density $=\rho$ and Tension $=T$ Now, we know that $f=\frac{c}{\lambda}$, $\therefore f=\frac{1}{2 L} \times \sqrt{\frac{T}{\mu}}$ where $\mu$ is mass per unit length And mass per unit length is related to density via, $\mu=\left(\pi \times \frac{D^2}{4}\right) \frac{1}{\rho}$ So, the frequency is $f=\frac{1}{2 L} \times \sqrt{\frac{T}{\left(\frac{\pi D^2}{4 \rho}\right)}}$ $\therefore f \propto \frac{1}{L D}$

Asked in: MHT CET 2022 (07 Aug Shift 1)

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