Question

'\(x\)' joule of heat is incident on a body. Out of it, the total heat reflected and transmitted by it is '\(y\)' joule. The absorption coefficient of the body is

• A. \(\frac{x}{y}\)
• B. \(\frac{x-y}{x}\)
• C. \(\frac{y}{x-y}\)
• D. \(\frac{x}{y-x}\)

Hint:

Absorptance equals absorbed heat divided by incident heat.

Answer 1

The Correct Option is B

Step 1: Use the three coefficients
$a+r+t=1$, where $r+t=y/x$.

Step 2: Solve
$a=1-\dfrac yx=\dfrac{x-y}{x}$, option (B).

Final Answer:
$a=(x-y)/x$, option (B). \[ \boxed{\dfrac{x-y}{x}} \]