A thin brass rectangular sheet of sides 15.0 cm and 10.0 cm is heated in a furnace to `500^@C` and then taken out. Calculate the electric power that is needed to maintain the sheet at this temperature, given that the emissivity is 0.250. (Stefan-Boltzmann constant, `sigma = 5.67 xx 10^(-8) Wm^(-2) K^(-4)` )

Explanation

To solve the problem, we need to calculate the electric power required to maintain the temperature of the brass sheet at 500°C using the Stefan-Boltzmann law. Here are the steps to find the solution:

### Step 1: Convert the dimensions of the sheet to meters
The dimensions of the brass sheet are given in centimeters. We need to convert them to meters for consistency with the units of the Stefan-Boltzmann constant.

- Length = 15.0 cm = 0.15 m
- Width = 10.0 cm = 0.10 m

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