Question

At a particular wavelength, if the reflectance of a body is \(0.4\), absorptance is \(0.5\), what is the transmittance for the same wavelength?

• A. 0.1
• B. 0.4
• C. 0.5
• D. 0.9

Hint:

Always remember the energy balance equation: \[ \boxed{ \text{Reflectance} + \text{Absorptance} + \text{Transmittance} = 1 } \]

Answer 1

The Correct Option is A

Concept: For any incident radiation, \[ \boxed{ \rho+\alpha+\tau=1 } \] where
• \(\rho\) = Reflectance
• \(\alpha\) = Absorptance
• \(\tau\) = Transmittance

Step 1: Substitute the given values. Given, \[ \rho=0.4,\qquad \alpha=0.5 \] \[ 0.4+0.5+\tau=1 \]

Step 2: Calculate transmittance. \[ \tau=1-0.9=0.1 \] Hence, \[ \boxed{\tau=0.1.} \] Therefore, the correct option is \[ \boxed{(A).} \]