Question

An engine is designed to convert 30% of heat energy into work. If the steam in the engine has 90KJ of heat energy, then the useful work done by the engine is ___.

• A. 16 kJ
• B. 20 kJ
• C. 27 kJ
• D. 17 kJ

Answer 1

The correct option is C 27 kJ

Total heat energy supplied = 90 kJ
Total amount of heat energy utilised for work = 30%
Total efficient work done by the engine = $90\times \frac{30}{100}kJ$
Hence, the work done = 27 kJ