Ncert Exercises & Solutions

Question 6.23:

A family uses 8 kW of power. (a) Direct solar energy is incident on the horizontal surface at an average rate of 200 W per square meter. If 20% of this energy can be converted to useful electrical energy, how large an area is needed to supply 8 kW? (b) Compare this area to that of the roof of a typical house.

(a) 200 m²

Power used by the family, P = 8 kW = 8 × 10⁸ W

Solar energy received per square meter = 200 W

The efficiency of conversion from solar to electricity energy = 20%

Area required to generate the desired electricity = A

As per the information given in the question, we have:

$8 \times 10^{3} = 20 % \times (A \times 200)$
$= \frac{20}{100} \times A \times 200$
$\Rightarrow A = \frac{8 \times 10^{3}}{40} = 200 m^{2}$

(b) The area of a solar plate required to generate 8 kW of electricity is almost equivalent to the area of the roof of a building having dimensions 14 m × 14 m.

NEET Information

courses

Company

Botany Questions

Chemistry Questions

Physics Questions

Zoology Questions