question_answer 4)

The wavelength range of visible spectrum extends from 400 nm to 750 nm. Express the frequency of the radiations in (\[Hz\]).

Answer:

\[{{v}_{1}}=\frac{c}{{{\lambda }_{1}}}=\frac{3\times {{10}^{8}}}{400\times {{10}^{-9}}}\] \[=7.5\times {{10}^{14}}{{\sec }^{-1}}or\,Hz\] \[{{v}_{2}}=\frac{c}{{{\lambda }_{2}}}=\frac{3\times {{10}^{8}}m{{s}^{-1}}}{750\times {{10}^{-9}}m}=4\times {{10}^{14}}{{\sec }^{-1}}or\,Hz\]