Question

The commonly used unit for the wavelength of light is ______.

Options

• angstrom

• metre

• light year

• none of these.

Answer 1

The commonly used unit for the wavelength of light is angstrom. 

Explanation:

Angstrom ($$1\text{ \AA} = 10^{-10}\text{ m}$$) is the traditional unit widely used to specify wavelengths of visible light (typically 4000 Å to 8000 Å). Metres and light years are too large for convenient optical wavelength measurements.