For any material, If R , T and A represent the reflection coefficient, transparent coefficient and absorption coefficient respectively, then for a blackbody which one of the following is true

Options

A. R = 1, T = 0, A = 0
B. R = 0, T = 1, A = 1
C. R = 0 , T = 0, A = 1
D. R = 0, T = 1, A = 0

Answer

To solve the problem, we need to analyze the properties of a blackbody in terms of its reflection coefficient (R), transmission coefficient (T), and absorption coefficient (A).

### Step-by-Step Solution:

1. **Understanding the Coefficients**:
- The reflection coefficient (R) represents the fraction of incident radiation that is reflected by the surface.
- The transmission coefficient (T) represents the fraction of incident radiation that passes through the material.
- The absorption coefficient (A) represents the fraction of incident radiation that is absorbed by the material.

2. **Relation Between the Coefficients**:
- For any material, the sum of the reflection, transmission, and absorption coefficients must equal 1:
\[ R + T + A = 1 \quad \text{(Equation 1)} \]

3. **Properties of a Blackbody**:
- A blackbody is an idealized physical object that absorbs all incident radiation, regardless of frequency or angle of incidence. Therefore, it does not reflect or transmit any radiation.
- This means that for a blackbody:
\[ A = 1 \quad \text{(it absorbs all incident radiation)} \]
\[ R = 0 \quad \text{(it reflects no radiation)} \]
\[ T = 0 \quad \text{(it transmits no radiation)} \]

4. **Substituting Values into Equation 1**:
- Now, substituting the values for a blackbody into Equation 1:
\[ R + T + A = 0 + 0 + 1 = 1 \]
- This confirms that the coefficients satisfy the equation.

5. **Conclusion**:
- For a blackbody, we have:
\[ R = 0, \quad T = 0, \quad A = 1 \]
- Therefore, the correct statement regarding the coefficients for a blackbody is that the reflection coefficient and transmission coefficient are both zero, while the absorption coefficient is one.

### Final Answer:
- The correct option is **C: R = 0, T = 0, A = 1**.