Q168 / 170 · Manipal (MET) 2018 · Physics
The mass defect in a particulạr nuclear reaction is 0.3 g . The amount of energy liberated in killowatt hour is (velocity of light $=3 \times 10^8 \mathrm{~m} / \mathrm{s}$ )
- A$1.5 \times 10^6$
- B$2.5 \times 10^6$
- C$3 \times 10^6$
- Correct answerD$7.5 \times 10^6$
Solution
$\begin{aligned} E & =\Delta m c^2 \\ E & =\frac{0.3}{1000} \times\left(3 \times 10^8\right)^2 \\ & =2.7 \times 10^{13} \mathrm{~J} \\ & =\frac{2.7 \times 10^{13}}{3.6 \times 10^6}=7.5 \times 10^6 \mathrm{kWh}\end{aligned}$
Hence, the correct answer is option: 'D'.