The ................ of the surface of a body is the ratio of amount of thermal radiations reflected in a given time to the total amount of thermal radiations incident.

Explanation

To solve the given problem, we need to identify the term that describes the ratio of the amount of thermal radiation reflected by a body to the total amount of thermal radiation incident on that body. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Concept of Thermal Radiation
Thermal radiation refers to the electromagnetic radiation emitted by all matter that has a temperature greater than absolute zero. When thermal radiation strikes a surface, it can be reflected, absorbed, or transmitted.

**Hint:** Think about what happens when light hits a surface. It can bounce off (reflect), be taken in (absorb), or pass through (transmit).

### Step 2: Identify the Components of Incident Radiation
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