Question

The sun delivers ${10}^{3}W{m}^{-2}$ of electromagnetic flux on the earth's surface. The total power that is incident on a roof of dimensions $6m\times 30m$ is

• A. $1.8\times {10}^{5}W$
• B. $7.2\times {10}^{5}W$
• C. $0.9\times {10}^{5}W$
• D. $4.5\times {10}^{5}W$

Answer 1

The correct option is A $1.8\times {10}^{5}W$

Given, electromagnetic flux $={10}^{3}W{m}^{-2}$
The area of roof $A=6m\times 30m$
$=180m^2$
The total power incident on roof
$P={10}^3\times 180$
$=1.8\times {10}^{5}W$