In the relation \(y=r \sin (\omega t-k x)\), the dimensions of \(\omega / k\) are

In the relation \(y=r \sin (\omega t-k x)\), the dimensions of \(\omega / k\) are
  1. \(\left[M^{0} L^{0} T^{0}\right]\)
  2. \(\left[M^{0} L^{1} T^{-1}\right]\)
  3. \(\left[M^{0} L^{0} T^{1}\right]\)
  4. \(\left[M^{0} L^{\prime} T^{0}\right]\)

Solution

$\begin{aligned} &\text{b. } y=r \sin (\omega t-k x) \\ &\text{Here, } \omega t=\text{angle } \Rightarrow \quad \omega=\frac{1}{T}=T^{-1} \\ &\text{Similarly, } k x=\text{angle } \Rightarrow \quad k=\frac{1}{x}=L^{-1} \\ &\therefore \quad \frac{\omega}{k}=\frac{T^{-1}}{L^{-1}}=L T^{-1} \end{aligned}$ Or simply \(\frac{\omega}{k}\) represents wave velocity \(\frac{\omega}{k}=\frac{2 \pi f}{2 \pi / \lambda}=f \lambda=v\), where \(f\) is frequency

Asked in: JEE Mains - Units and Dimensions - Chapter Test

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