Question

One milligram of matter converted into energy will give

• A. 90 J
• B. $ 9 \times 10^3 \, J $
• C. $ 9 \times 10^{10} \, J $
• D. $ 9 \times 10^5 \, J $

Answer 1

Answer: (C)

Given, mass of the matter $= 1 \,mg=1\times10^{-6}\,kg$
As we know, $C=3\times10^{8} m /s$
Matter will be converted into energy by the formula, $E=mc^{2}$
$=1\times10^{-6}\times\left(3\times10^{8}\right)^{2}$
$=1\times10^{-6}\times9\times10^{16}$
$=9\times10^{10}\,J$