KVPY SA Exam 2013 Question Paper

Solar energy is incident normally on the earth’s surface at the rate of about 1.4 $\mathrm{kW}{\mathrm{m}}^{-2}$. The distance between the earth and the sun is $1.5\times {10}^{11}\mathit{m}$. Energy (E) and mass (m) are related by Einstein equation $\mathrm{E}={\mathrm{mc}}^2$ where c $\left(3\times {10}^8{\mathrm{ms}}^{-1}\right)$ is the speed of light in free space. The decrease in the mass of the sun is