Class 11 Physics - Chapter Thermodynamics NCERT Solutions | A steam engine delivers 5.4 x 108 J of w
A steam engine delivers 5.4 x 108 J of work per minute and services 3.6 x 109 J of heat per minute from its boiler. What is the efficiency of the engine? How much heat is wasted per minute?
Work done by the steam engine per minute, W = 5.4 × 108 J
Heat supplied from the boiler, H = 3.6 × 109 J
Efficiency of the engine = Output energy / Input energy
∴ n = W / H
= 5.4 × 108 / 3.6 × 109
Hence, the percentage efficiency of the engine is 15 %.
Amount of heat wasted = 3.6 × 109 - 5.4 × 108
= 30.6 × 108 = 3.06 × 109 J
Therefore, the amount of heat wasted per minute is 3.06 × 109 J.
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