Q12.7 A steam engine delivers5.4\times 10^8\ J of work per minute and services 3.6\times 10^9\ J of heat per minute from its boiler. What is the efficiency of the engine? How much heat is wasted per minute?

Answers (1)
S Sayak

Output = 5.4\times 10^8\ J

Input = 3.6\times 10^9\ J

Efficiency is \eta

\\\eta =\frac{output}{input}\\ \eta =\frac{5.4\times 10^{8}}{3.6\times 10^{9}}\\ \eta =0.15

The efficiency of the engine is 0.15.

The percentage efficiency of the engine is 15%.

Heat wasted per minute = Heat produced per minute - useful work done per minute

                                        \\=3.6\times 10^{9}-5.4\times 10^{8}\\ =3.06\times 10^{9}\ J\ min^{-1}