Question

Colour of light is determined by its:
A. wavelength
B. frequency
C. velocity
D. amplitude

Answer 1

We know that light interacts in three ways these are reflection, absorption and transmission. We see the transmitted light. White light is combined with seven colours such as VIBGYOR (violet, indigo, blue, green, yellow orange, red).

Complete step by step answer:
Amplitude is used in the determination of intensity not in colour of light. When the light wave passes through a denser medium the colour remains the same while the speed decreases. We have studied that the colour is caused by the absorption of a specific wavelength The colour of light is determined by the wavelength of light. We know that wavelength is the distance between successive crests of a wave. The red light possesses the longest wavelength while violet has the shortest wavelength. The wavelength changes according to the medium. When a light wave enters a glass the wavelength decreases while frequency remains constant. The range of wavelength or frequency for waves is also known as spectrum. We have studied that $E = hv$ where $E$ is energy and $v$ is frequency and h is planck's constant, we know that frequency remains constant when the light travels through different mediums so the energy will also remain constant . Hence the energy of light and frequency is not used in determination of the colour of light.

So, the correct answer is “Option A”.

Note: We have seen the impact of wavelength, frequency, velocity and amplitude on the colour of light waves and we concluded that only wavelength is helpful in the determination of the colour of light.