Question

In nuclear fusion, One gram hydrogen is converted into 0.993gm. Ifthe efficiency of the generator
be 5%, then the energy obtained in KWH is
1) 8.75×103 2 4.75×10 3) 5.75×103 4) 3.73x103​

Answer 1

answer : option (1) 8.75 × 10³ KWh

explanation : one gram hydrogen is converted into 0.993gm.

so, rest mass = 1g - 0.993g = 0.007g

from Enstien's rest mass energy,

E = mc²

= 0.007g × (3 × 10^8m/s)²

= 7 × 10^-3 × 10^-3 kg × 9 × 10^16 m²/s²

= 7 × 9 × 10^10 J

= 63 × 10^ 10 J

as efficiency of generator is 5%

so, energy obtained = 5 % of 63 × 10^10 J

= 5/100 × 63 × 10^10 J

= 63 × 5 × 10^8 J

as we know, 1KWh = 3.6 × 10^6 J

so, energy obtained in KWh = 63 × 5 × 10^8/3.6 × 10^6

= 8.75 × 10³ KWh

hence, option (1) is correct choice.