0 votes 0 votes For an opaque surface, the absorptivity ($\alpha$), transmissivity ($\tau$) and reflectivity ($\rho$) are related by the equation $\alpha + \rho = \tau$ $\rho + \alpha + \tau =0$ $\alpha + \rho =1$ $\alpha + \rho =0$ Fluid Mechanics gateme-2012 fluid-mechanics-and-thermal-science + – Andrijana3306 asked Mar 19, 2018 • recategorized Mar 3, 2021 by Lakshman Bhaiya Andrijana3306 1.5k points 1 61 70 answer See all 0 reply