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In an air-standard Otto cycle, air is supplied at 0.1 MPa and 308 K. The ratio of the specific heats (γ) and the specific gas constant (R) of air are 1.4 and 288.8 J/kgK, respectively. If the compression ratio is 8 and the maximum temperature in the cycle is 2660 K, the heat (in kJ/kg) supplied to the engine is ______.
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- 1418
- 1416.39
- 1416.27
- 1416
Correct Option: C
Otto cycle 
Given: P1 = 0.1 MPa
T1 = 308 K
γ = 1.4
R = 0.2888 kJ/kg.k
T3 = 2660 K
(1-2) Isentropic compression
PVr = constant
| = | = (r)γ - 1 | T1 |
T2 = 308 × 80.4 = 698.40 k
(2-3) Isochoric Heat addition process
| = | = 1.4 | Cv |
R = 0.2888 kJ/kg
Cp – Cv = 0.2888
| Cv |  | - 1 |  | = 0.2888 | Cv |
| Cv = | = 0.722 kJ /kg | 1.4 - 1 |
Qin = Cv (T3 – T2) = 0.722 (2660 – 698.40)
= 1416.27 kJ/kg
