A black body is at a temperature `300 K`. It emits energy at a rate, which is proportional to

Options

A. 300
B. `(300)^(3)`
C. `(300)^(2)`
D. `(300)^(4)`

Explanation

To solve the question regarding the rate at which a black body emits energy at a temperature of 300 K, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of a Black Body**:
A black body is an idealized physical object that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. It is also a perfect emitter of radiation.

2. **Refer to the Stefan-Boltzmann Law**:
The Stefan-Boltzmann Law states that the total energy radiated per unit surface area of a black body is directly proportional to the fourth power of its absolute temperature (T). Mathematically, this can be expressed as:
\[ E \propto T^4 \]
where \(E\) is the energy emitted per unit area and \(T\) is the absolute temperature in Kelvin.

3. **Apply the Law to the Given Temperature**:
In this case, the temperature \(T\) is given as 300 K. According to the Stefan-Boltzmann Law, the energy emitted by the black body can be expressed as:
\[ E \propto (300)^4 \]

4. **Conclusion**:
Therefore, the rate at which the black body emits energy is proportional to \(300^4\).

### Final Answer:
The energy emitted by the black body at 300 K is proportional to \(300^4\).