Respuesta :
Answer:
The efficiency of an engine is 80%.
(A) is correct option.
Explanation:
Given that,
Work done = 576 J
Supplied heat = 720 J
Exhausts of heat = 144 J
We need to calculate the efficiency
Using formula of efficiency
[tex]\eta=1-\dfrac{Q_{2}}{Q_{1}}[/tex]
Where, Q₁ = Supplied heat
Q₂ = Exhausts of heat
Put the value into the formula
[tex]\eta=1-\dfrac{144}{720}[/tex]
[tex]\eta=0.8\times100[/tex]
[tex]\eta=80\%[/tex]
Hence, The efficiency of an engine is 80%.