The relation between the velocity of light (c), frequency (v) and wavelength (λ) is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \(c=v\lambda\)
In one second a source sends out v waves (its frequency), and each wave is λ long (its wavelength). The distance the light travels in one second, its speed, is therefore the number of waves times the length of each: speed = frequency × wavelength.
\(c=v\lambda\), so the frequency is \(v=\frac{c}{\lambda}\) and the wavelength \(\lambda=\frac{c}{v}\)
The other three relations do not follow from it: \(v=c\lambda\) multiplies where it should divide, \(v=\frac{\lambda}{c}\) has the fraction upside down, and \(\lambda=\frac{1}{vc}\) does not even have the units of a length.