Question

What is the range of wavelength of the spectrum of white light in nm?
A. 400nm to 500nm
B. 500nm to 600nm
C. 600nm to 800nm
D. All of the above

Answer 1

Hint:White color consists of all the colors that one can see in a rainbow of seven colors (that is violet, indigo, blue, green, yellow, orange and red). These seven colors form a band that is actually the visible band (the visible band spectrum) of the electromagnetic spectrum. The electromagnetic spectrum consists of a wide range of wavelengths. Therefore, the white light can consist of all the wavelengths from the visible spectrum.

Complete answer:
The electromagnetic spectrum is divided into a wide range of waves that have different wavelengths or frequencies. For example, radio waves, microwaves, infrared rays, ultraviolet rays, X-rays and gamma rays. These waves are arranged in terms of increasing order of frequency and energy and decreasing order of wavelength. The wavelengths or frequencies of the above mentioned spectrum is not visible to human eyes.

The only visible spectrum is known as the visible spectrum. It ranges approximately from 380nm to 700nm and lies in between the ultraviolet and infrared rays in the electromagnetic spectrum. The visible spectrum is roughly measured from 300nm to 800nm.

This visible spectrum consists of colors from violet, indigo, blue, green, yellow, orange and red. If a mixture of all the wavelengths of the visible spectrum is made, then a beam of white light is obtained. The colors of the visible spectrum can be easily seen in a rainbow.Options A, B and C contain all the wavelengths of the visible spectrum.

Hence, option D is the correct answer.

Note:The visible spectrum has a range of frequencies which are visible and these rays can be absorbed by a human eye. But this visible range for humans is actually not the visible range for animals. Most of the underwater creatures have a visible sight towards Ultra-Violet radiations.Also, note that the visible spectrum is also sometimes referred to as the white light spectrum as white color is the mixture of all the colors of the visible spectrum.