Energetics

An engineer claims to have developed an engine which develops 3.4 kW while consuming 0.44 Kg of fuel of calorific value of calorific value of 41870 kJ / kg in one hour. The maximum and minimum temperatures recorded in the cycle are 1400 °C & 350 °C respectively. is the claim of the engineer genuine ?

6 Answers

106
Asish Mahapatra ·

efficiency (max) = 1-T1/T2 = 1-(350+273)/(1400+273) = 0.628

Now heat supplied (1hr) = 0.44*41870 = 18422.8 kJ

work done (1hr) = 3.4*3600 kJ = 12240 kJ

efficiency = 12240/18422.8 > 0.628

so it is NOT genuine

edit: missed out the time..

1
mentor_Layak Singh ·

@ Ashish Your answer is not correct .
Read it carefully and explain you answer !!!

11
virang1 Jhaveri ·

Efficiency = 1400-350/1673= 1050/1673 = 0.628 =E

Heat supplied = 0.44*41870kJ in 1 hour
Work done = 3.4K*3600 in 1Hour

Effi.=e=3.4K*3600/0.44*41870K = 0.664
e>E Hence it is not genuine

106
Asish Mahapatra ·

yup got my answer

edited above

1
Unicorn--- Extinct!! ·

I'm getting "the claim of the engineer is genuine"
Kuch mistake kari hogi maine...[2]

1
mentor_Layak Singh ·

not it's not genuine !!!

Your Answer

Close [X]