question_answer

Wave length of yellow light is\[\text{589}\,{{A}^{0}}\]. If speed of light in air is\[\text{3}\times \text{1}{{0}^{\text{8}}}\text{ m}{{\text{s}}^{-\text{1}}}.\]What is the frequency of vibrations?

Answer:

Given \[\lambda =5890{{A}^{0}}=5890\times {{10}^{10}}m\] \[v=3\times {{10}^{10}}cm/s=3\times {{10}^{8}}m/s\] \[n=?\] We know, \[V=n\lambda \] \[\Rightarrow \] \[n=\frac{V}{\lambda }=\frac{3\times {{10}^{8}}}{5890\times {{10}^{-10}}}\] \[=\frac{3}{589}\times {{10}^{17}}=5\times {{10}^{14}}Hz\].