Question

Which of the following colours of light has the lowest frequency?
A) Yellow
B) Violet
C) Orange
D) Blue
E) Green

Answer 1

All of the colours that we can see are a part of the visible spectrum of light. The visible spectrum of light has frequencies ranging from $400 - 790{\text{THz}}$.

Complete answer:
The visible light spectrum is the segment of the electromagnetic spectrum that the human eye can view. More simply, this range of wavelengths or the corresponding range of frequencies is called visible light. Typically, the human eye can detect wavelengths from 380 to 700 nanometres. Different colours have different frequencies which is why our eyes can detect them in the form of different colours. The frequency bands of different colors are as follows:

Color	Frequency
Violet	670–790 THz
Blue	620–670 THz
Cyan	600–620 THz
Green	530–600 THz
Yellow	510–530 THz
Orange	480–510 THz
Red	400–480 THz

We can see that the colour Orange has the lowest frequency among the choices given. Hence the correct is option (C).

Note: We can also answer this question by remembering the sequence of colours which is often remembered as ‘VIBGYOR’ with each letter corresponding to the initial letter of each colour. ‘VIBGYOR’ is written in the order of decreasing frequency so, among the options, we can see that Orange has the lowest frequency while in general, Red has the lowest frequency. The colour ranges given in the solution are approximate and there is no fixed boundary but the colours rather continuously mix into each other rather than changes in a sharp manner.