Answer:
25%
Explanation:
Efficiency of an engine is calculated by dividing the energy output over the energy input and expressing that as a percentage.
Efficiency = [tex]\frac{energy output}{energy input}[/tex] x 100%
Given,
Heat input = 1000 J
Heat wasted = 750 J
Heat used = 1000 J – 750 J = 250 J
Efficiency = [tex]\frac{250 J }{1000 J}[/tex] x 100% = 25%
