An aluminiumum foil of relative emittance 0.1 is placed in between two concentric spheres at temperatures 300K and 200k respectively. Calculate the temperature of the foil after the steady state is reached . Assume that the spheres are perfect black body radiators. Also calculate the rater of energy transfer between one of the spheres and the foil.
`[sigma=5.67xx10^(-8)` S.I. Unit]

Explanation

To solve the problem step by step, we will use the Stefan-Boltzmann law and the concept of thermal equilibrium.

### Step 1: Understand the Problem
We have an aluminum foil with a relative emittance (ε) of 0.1 placed between two concentric spheres at temperatures T1 = 300 K and T2 = 200 K. We need to find the temperature of the foil (Tf) when steady state is reached and the rate of energy transfer between one of the spheres and the foil.

### Step 2: Apply the Stefan-Boltzmann Law
The Stefan-Boltzmann law states that the power radiated by a black body is proportional to the fourth power of its absolute temperature. For a body with emissivity ε, the power radiated is given by:

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