The emissive power of a black body at `T=300K` is `100Watt//m^(2)` consider a body B of area `A=10m^(2)` coefficient of reflectivity `r=0.3` and coefficient of transmission `t=0.5` its temperature is 300 K. then which of the followin is correct:

Options

A. The emissive power of B is `20W//m^(2)`
B. the emissive power of B is `200W//m^(2)`
C. the power emitted by B is `200watts`
D. the emissivity of `B` is `=0.2`

Explanation

To solve the problem step by step, we need to determine the emissive power of body B and then calculate the total power emitted by it.

### Step 1: Understand the given data
- Emissive power of a black body at T = 300 K, \( E_{black} = 100 \, \text{W/m}^2 \)
- Area of body B, \( A = 10 \, \text{m}^2 \)
- Coefficient of reflectivity, \( r = 0.3 \)
- Coefficient of transmission, \( t = 0.5 \)
- Temperature of body B, \( T = 300 \, \text{K} \)
...