Question

What is the unit of transmittance?

• A. cm sec^−1
• B. cm^−1
• C. It is unitless
• D. sec^−1

Answer 1

Answer:

C. It is unitless

Transmittance is a dimensionless quantity and hence unitless. Transmittance is defined as the ratio of the transmitted radiant flux to the incident radiant flux in a medium. It is a dimensionless number that, like reflectance, ranges from 0 to 1 for nonfluorescent materials, with the total transmittance being the sum of regular and diffuse transmittance.