A Carnot engine operates between 400 K and 300 K. If it absorbs 800 J from the hot reservoir per cycle, the work output per cycle is:

1. η = 1 − T₂/T₁ = 1 − 300/400 = 0.25 (25 %). 2. W = η × Q₁ = 0.25 × 800 = 200 J. 3. Heat rejected Q₂ = Q₁ − W = 600 J (a useful cross-check). _Source: syllabus Physics Ch 11, §11.10 Carnot Engine_