Answer: a) [tex]Frequency=666\times10^{12}Hz-789\times10^{12}Hz[/tex]
b) [tex]Wavelength=380nm-450nm[/tex]
Explanation: Visible light is a form of electromagnetic wave.
Wavelength is defined as the distance between two successive crests of a wave. It is represented as symbol [tex]\lambda[/tex].
Frequency is defined as the number of complete cycles happening per second. It is represented by the symbol [tex]\nu[/tex].
Wavelength and Frequency follow inverse relation,
[tex]\nu=\frac{c}{\lambda}[/tex]
where, c = speed of light = [tex]3\times10^8m/s[/tex]
Wavelength and frequency of a wave is usually expressed in a range.
a) [tex]\text{Frequency of visible light}=666\times10^{12}Hz-789\times10^{12}Hz[/tex]
b) [tex]\text{Wavelength of visible light}=380nm-450nm[/tex]