MHTCET 14 May 2023 Shift 2 Solved Paper

To calculate the frequency of light when the wavelength is given, we can use the relationship between speed, frequency, and wavelength. This relationship is given by the equation:$c=\lambda \cdot \nu$where:$c$ is the speed of light in a vacuum $(c \approx 3 \times 10^8\ \text{m/s})$,$\lambda$ is the wavelength in meters,$\nu(\nu)\;\text{ is the frequency in hertz }\;(\text{Hz})\;\text{ . }\;$To find the frequency, we can rearrange the equation to solve for $\nu$ :$\nu=\frac{c}{\lambda}$ Given that the wavelength is $750\text{ nm}$ (nanometers), we have to convert the wavelength into meters for our calculations because the speed of light is in meters per second. There are $1 \times 10^9$ nanometers in one meter, so:$750\text{ nm}=750 \times 10^{-9}\text{ m}$Now, let's insert the values for $c$ and $\lambda$ into our equation:$\nu = \frac{3 \times 10^8\ \text{m/s}}{750 \times 10^{-9}\ \text{m}}$Calculating the frequency $\nu$ :$\;\nu = \frac{3 \times 10^8}{750 \times 10^{-9}} = \frac{3 \times 10^8}{0.75 \times 10^{-6}} = \frac{3}{0.75} \times 10^{8+6}$$\;\nu = 4 \times 10^{14}\ \text{Hz}$Therefore, the frequency of light with a wavelength of $750\text{ nm}$ is $4 \times 10^{14}\ \text{Hz}$, which corresponds to Option B.