Which one among the following colours has the highest wavelength ?

The visible light spectrum consists of electromagnetic radiation with wavelengths ranging approximately from 400 nm to 700 nm [1]. The sequence of colors in this spectrum is commonly remembered by the acronym VIBGYOR: Violet, Indigo, Blue, Green, Yellow, Orange, and Red [3]. Within this range, wavelength decreases and energy increases as one moves from red to violet. Red light occupies the long-wavelength end of the spectrum, measuring approximately 625 nm to 750 nm. In contrast, violet light has the shortest wavelength, measuring around 380 nm to 400 nm [2]. Specifically, red light has a wavelength about 1.8 times greater than blue light [1]. Among the options provided—Violet, Green, Yellow, and Red—Red possesses the highest wavelength, while Violet possesses the lowest [3].

Sources

1. [1] https://education.nationalgeographic.org/resource/visible-light/
2. [3] Science , class X (NCERT 2025 ed.) > Chapter 10: The Human Eye and the Colourful World > 10.6.2 Why is the colour of the clear Sky Blue? > p. 169
3. [2] Science , class X (NCERT 2025 ed.) > Chapter 10: The Human Eye and the Colourful World > Activity 10.2 > p. 167