Ram used to live in a remote village of Rajasthan which didn’t have electricity. He was a good student and studied very hard to become an engineer in spite of all hardships. While studying, he came to know that solar energy can be converted to electrical energy by using specially designed devices.
He went to his village and discussed it with villagers. He also told them that Govt. also gives subsidy for using solar devices. All the villagers agreed and they contacted the Govt. officials who obliged their request and the village became the model village which used solar energy for electricity.
(ii) If direct solar energy is incident on the horizontal surface at an average rate of 200 watt per square metre and 20% of this energy can be converted to use electrical energy, then how much area is needed to supply 8 KW of electrical energy?

Explanation

To solve the problem step by step, we need to determine the area required to supply 8 kW (or 8000 watts) of electrical energy using solar energy that is incident at a rate of 200 watts per square meter, with 20% of that energy being converted to electrical energy.

### Step 1: Calculate the effective electrical energy generated per square meter.
The solar energy incident on the surface is given as 200 watts/m². However, only 20% of this energy can be converted to electrical energy.

\[ \text{Electrical energy per square meter} = 200 \, \text{watts/m}^2 \times 0.20 = 40 \, \text{watts/m}^2 \]
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