Question

In a thermo-nuclear reaction, ${10}^{-3}$Kg of Hydrogen is converted into $0.99\times {10}^{-3}$kg of Helium. If the efficiency of the generator is $50\%$, the electrical energy generated in KWH is

• A. ${10}^5$
• B. $1.5\times {10}^5$
• C. $1.25\times {10}^5$
• D. $1.3\times {10}^5$

Answer 1

Answer: (C)

$1.25\times {10}^5$

$2{}_1{H}^2\to 2H{e}^4$
Change in mass = $\Delta M=0.01\times {10}^{-3}Kg$
Energy = $\Delta m{c}^2={10}^{-5}(3\times {10}^8{)}^{2}J=9\times {10}^{11}j$
Efficiency $=0.5$
Electrical energy = $0.5\times E=4.5\times {10}^{11}J=1.25\times {10}^{5}KWh$
( 1KWh = 3600000 J)