A nuclear reactor delivers a power of 10⁹ W . What is the amount of fuel consumed by the reactor in one hour :

Correct Answer: (A) 0.04 g

Using Einstein's mass-energy equivalence E = mc², the mass consumed per second is m = P/c². For a power P = 10⁹ W over one hour (3600 s), the total energy is E = 10⁹ × 3600 J, yielding a mass consumption of approximately 0.04 g.