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 Imagine that a reactor converts all given mass into energy and that it operates at a power level of 109 watt.  The mass of the fuel consumed per hour in the reactor will be :  (velocity of light, c is 3×108 m/s)

  • Option 1)

        0.96 gm

  • Option 2)

     0.8 gm

  • Option 3)

     4×10−2 gm

  • Option 4)

     6.6×10−5 gm



Answers (1)


As we learnt in

energy mass equivalence -

\Delta E=\Delta m.c^{2}       

- wherein

\Delta m = mass defect

\Delta E = energy released



 Amount of energy produced in 

11\ hour=3600\times 10^{9}J=3.6\times10^{12}J

This energy is produced by converting mass into energy so \Delta mc^{2}=3.6\times10^{12}

\Delta m=\frac{3.6\times10^{12}}{9\times10^{16}}=0.4\times10^{-4}kg

\Delta m=4\times10^{-2}gm

Correct option is 3.

Option 1)

    0.96 gm

This is an incorrect option.

Option 2)

 0.8 gm

This is an incorrect option.

Option 3)

 4×10−2 gm

This is the correct option.

Option 4)

 6.6×10−5 gm


This is an incorrect option.

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